switch to xmake for package management (#611)

This change removes our dependency on vcpkg for package management, in favour of bringing some code in-tree in the `thirdparty` folder as well as using the xmake build-in package management feature. For the latter, all the package definitions are maintained in the zen repo itself, in the `repo` folder.

It should now also be easier to build the project as it will no longer depend on having the right version of vcpkg installed, which has been a common problem for new people coming in to the codebase. Now you should only need xmake to build.

* Bumps xmake requirement on github runners to 2.9.9 to resolve an issue where xmake on Windows invokes cmake with `v144` toolchain which does not exist
* BLAKE3 is now in-tree at `thirdparty/blake3`
* cpr is now in-tree at `thirdparty/cpr`
* cxxopts is now in-tree at `thirdparty/cxxopts`
* fmt is now in-tree at `thirdparty/fmt`
* robin-map is now in-tree at `thirdparty/robin-map`
* ryml is now in-tree at `thirdparty/ryml`
* sol2 is now in-tree at `thirdparty/sol2`
* spdlog is now in-tree at `thirdparty/spdlog`
* utfcpp is now in-tree at `thirdparty/utfcpp`
* xmake package repo definitions is in `repo`
* implemented support for sanitizers. ASAN is supported on windows, TSAN, UBSAN, MSAN etc are supported on Linux/MacOS though I have not yet tested it extensively on MacOS
* the zencore encryption implementation also now supports using mbedTLS which is used on MacOS, though for now we still use openssl on Linux
* crashpad
* bumps libcurl to 8.11.0 (from 8.8.0) which should address a rare build upload bug

1 files changed, 3924 insertions, 0 deletions

diff --git a/thirdparty/ryml/test/test_tree.cpp b/thirdparty/ryml/test/test_tree.cpp
new file mode 100644
index 000000000..b6aad0435
--- /dev/null
+++ b/thirdparty/ryml/test/test_tree.cpp
@@ -0,0 +1,3924 @@
+#ifndef RYML_SINGLE_HEADER
+#include "c4/yml/std/std.hpp"
+#include "c4/yml/parse.hpp"
+#include "c4/yml/emit.hpp"
+#include <c4/format.hpp>
+#include <c4/yml/detail/checks.hpp>
+#include <c4/yml/detail/print.hpp>
+#endif
+#include "./test_case.hpp"
+#include "./callbacks_tester.hpp"
+
+#include <gtest/gtest.h>
+
+#if defined(_MSC_VER)
+#   pragma warning(push)
+#   pragma warning(disable: 4389) // signed/unsigned mismatch
+#elif defined(__clang__)
+#   pragma clang diagnostic push
+#   pragma clang diagnostic ignored "-Wdollar-in-identifier-extension"
+#elif defined(__GNUC__)
+#   pragma GCC diagnostic push
+#endif
+
+namespace c4 {
+namespace yml {
+
+
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+
+void node_scalar_test_empty(NodeScalar const& s)
+{
+    EXPECT_TRUE(s.empty());
+    EXPECT_EQ(s.tag, "");
+    EXPECT_EQ(s.tag.len, 0u);
+    EXPECT_TRUE(s.tag.empty());
+    EXPECT_EQ(s.scalar, "");
+    EXPECT_EQ(s.scalar.len, 0u);
+    EXPECT_TRUE(s.scalar.empty());
+}
+
+void node_scalar_test_foo(NodeScalar const& s, bool with_tag=false)
+{
+    EXPECT_FALSE(s.empty());
+    if(with_tag)
+    {
+        EXPECT_EQ(s.tag, "!!str");
+        EXPECT_EQ(s.tag.len, 5u);
+        EXPECT_FALSE(s.tag.empty());
+    }
+    else
+    {
+        EXPECT_EQ(s.tag, "");
+        EXPECT_EQ(s.tag.len, 0u);
+        EXPECT_TRUE(s.tag.empty());
+    }
+    EXPECT_EQ(s.scalar, "foo");
+    EXPECT_EQ(s.scalar.len, 3u);
+    EXPECT_FALSE(s.scalar.empty());
+}
+
+void node_scalar_test_foo3(NodeScalar const& s, bool with_tag=false)
+{
+    EXPECT_FALSE(s.empty());
+    if(with_tag)
+    {
+        EXPECT_EQ(s.tag, "!!str+++");
+        EXPECT_EQ(s.tag.len, 8u);
+        EXPECT_FALSE(s.tag.empty());
+    }
+    else
+    {
+        EXPECT_EQ(s.tag, "");
+        EXPECT_EQ(s.tag.len, 0u);
+        EXPECT_TRUE(s.tag.empty());
+    }
+    EXPECT_EQ(s.scalar, "foo3");
+    EXPECT_EQ(s.scalar.len, 4u);
+    EXPECT_FALSE(s.scalar.empty());
+}
+
+TEST(NodeScalar, ctor_empty)
+{
+    NodeScalar s;
+    node_scalar_test_empty(s);
+}
+
+TEST(NodeScalar, ctor__untagged)
+{
+    {
+        const char sarr[] = "foo";
+        const char *sptr = "foo";
+        csubstr ssp = "foo";
+
+        for(auto s : {NodeScalar(sarr), NodeScalar(to_csubstr(sptr)), NodeScalar(ssp)})
+        {
+            node_scalar_test_foo(s);
+        }
+
+        NodeScalar s;
+        s = {sarr};
+        node_scalar_test_foo(s);
+        s = to_csubstr(sptr);
+        node_scalar_test_foo(s);
+        s = {ssp};
+        node_scalar_test_foo(s);
+    }
+
+    {
+        const char sarr[] = "foo3";
+        const char *sptr = "foo3";
+        csubstr ssp = "foo3";
+
+        for(auto s : {NodeScalar(sarr), NodeScalar(to_csubstr(sptr)), NodeScalar(ssp)})
+        {
+            node_scalar_test_foo3(s);
+        }
+
+        NodeScalar s;
+        {
+            SCOPED_TRACE("here 1");
+            s = {sarr};
+            node_scalar_test_foo3(s);
+        }
+        {
+            SCOPED_TRACE("here 2");
+            s = to_csubstr(sptr);
+            node_scalar_test_foo3(s);
+        }
+        {
+            SCOPED_TRACE("here 3");
+            s = ssp;
+            node_scalar_test_foo3(s);
+        }
+    }
+}
+
+TEST(NodeScalar, ctor__tagged)
+{
+    {
+        const char sarr[] = "foo", tarr[] = "!!str";
+        const char *sptr = "foo";
+        const char *tptr = "!!str";
+        csubstr ssp = "foo", tsp = "!!str";
+
+        for(NodeScalar s : {
+                NodeScalar(tsp, ssp),
+                    NodeScalar(tsp, to_csubstr(sptr)),
+                    NodeScalar(tsp, sarr),
+                NodeScalar(to_csubstr(tptr), ssp),
+                    NodeScalar(to_csubstr(tptr), to_csubstr(sptr)),
+                    NodeScalar(to_csubstr(tptr), sarr),
+                NodeScalar(tarr, ssp),
+                    NodeScalar(tarr, to_csubstr(sptr)),
+                    NodeScalar(tarr, sarr),
+        })
+        {
+            node_scalar_test_foo(s, true);
+        }
+
+        NodeScalar s;
+
+        {
+            SCOPED_TRACE("here 0.0");
+            s = {tsp, ssp};
+            node_scalar_test_foo(s, true);
+        }
+        {
+            SCOPED_TRACE("here 0.1");
+            s = {tsp, to_csubstr(sptr)};
+            node_scalar_test_foo(s, true);
+        }
+        {
+            SCOPED_TRACE("here 0.2");
+            s = {tsp, sarr};
+            node_scalar_test_foo(s, true);
+        }
+
+        {
+            SCOPED_TRACE("here 1.0");
+            s = {to_csubstr(tptr), ssp};
+            node_scalar_test_foo(s, true);
+        }
+        {
+            SCOPED_TRACE("here 1.1");
+            s = {to_csubstr(tptr), to_csubstr(sptr)};
+            node_scalar_test_foo(s, true);
+        }
+        {
+            SCOPED_TRACE("here 1.3");
+            s = {to_csubstr(tptr), sarr};
+            node_scalar_test_foo(s, true);
+        }
+
+        {
+            SCOPED_TRACE("here 3.0");
+            s = {tarr, ssp};
+            node_scalar_test_foo(s, true);
+        }
+        {
+            SCOPED_TRACE("here 3.1");
+            s = {tarr, to_csubstr(sptr)};
+            node_scalar_test_foo(s, true);
+        }
+        {
+            SCOPED_TRACE("here 3.3");
+            s = {tarr, sarr};
+            node_scalar_test_foo(s, true);
+        }
+
+    }
+
+    {
+        const char sarr[] = "foo3", tarr[] = "!!str+++";
+        const char *sptr = "foo3";
+        const char *tptr = "!!str+++";
+        csubstr ssp = "foo3", tsp = "!!str+++";
+
+        NodeScalar wtf = {tsp, ssp};
+        EXPECT_EQ(wtf.tag, tsp);
+        EXPECT_EQ(wtf.scalar, ssp);
+        for(auto s : {
+                NodeScalar(tsp, ssp),
+                    NodeScalar(tsp, to_csubstr(sptr)),
+                    NodeScalar(tsp, sarr),
+                NodeScalar(to_csubstr(tptr), ssp),
+                    NodeScalar(to_csubstr(tptr), to_csubstr(sptr)),
+                    NodeScalar(to_csubstr(tptr), sarr),
+                NodeScalar(tarr, ssp),
+                    NodeScalar(tarr, to_csubstr(sptr)),
+                    NodeScalar(tarr, sarr),
+        })
+        {
+            node_scalar_test_foo3(s, true);
+        }
+
+        NodeScalar s;
+
+        {
+            SCOPED_TRACE("here 0.0");
+            s = {tsp, ssp};
+            node_scalar_test_foo3(s, true);
+        }
+        {
+            SCOPED_TRACE("here 0.1");
+            s = {tsp, to_csubstr(sptr)};
+            node_scalar_test_foo3(s, true);
+        }
+        {
+            SCOPED_TRACE("here 0.3");
+            s = {tsp, sarr};
+            node_scalar_test_foo3(s, true);
+        }
+
+        {
+            SCOPED_TRACE("here 1.0");
+            s = {to_csubstr(tptr), ssp};
+            node_scalar_test_foo3(s, true);
+        }
+        {
+            SCOPED_TRACE("here 1.1");
+            s = {to_csubstr(tptr), to_csubstr(sptr)};
+            node_scalar_test_foo3(s, true);
+        }
+        {
+            SCOPED_TRACE("here 1.3");
+            s = {to_csubstr(tptr), sarr};
+            node_scalar_test_foo3(s, true);
+        }
+
+        {
+            SCOPED_TRACE("here 3.0");
+            s = {tarr, ssp};
+            node_scalar_test_foo3(s, true);
+        }
+        {
+            SCOPED_TRACE("here 3.1");
+            s = {tarr, to_csubstr(sptr)};
+            node_scalar_test_foo3(s, true);
+        }
+        {
+            SCOPED_TRACE("here 3.3");
+            s = {tarr, sarr};
+            node_scalar_test_foo3(s, true);
+        }
+
+    }
+
+}
+
+
+
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+
+TEST(NodeInit, ctor__empty)
+{
+    NodeInit n;
+    EXPECT_EQ((type_bits)n.type, (type_bits)NOTYPE);
+    EXPECT_EQ(n.key.scalar, "");
+    EXPECT_EQ(n.key.tag, "");
+    EXPECT_EQ(n.val.scalar, "");
+    EXPECT_EQ(n.val.tag, "");
+}
+
+TEST(NodeInit, ctor__type_only)
+{
+    for(auto k : {KEY, KEYVAL, MAP, KEYMAP, SEQ, KEYSEQ})
+    {
+        SCOPED_TRACE(NodeType::type_str(k));
+        NodeInit n(k);
+        EXPECT_EQ((type_bits)n.type, (type_bits)k);
+        EXPECT_EQ(n.key.scalar, "");
+        EXPECT_EQ(n.key.tag, "");
+        EXPECT_EQ(n.val.scalar, "");
+        EXPECT_EQ(n.val.tag, "");
+    }
+}
+
+TEST(NodeInit, ctor__val_only)
+{
+    {
+        const char sarr[] = "foo";
+        const char *sptr = "foo"; size_t sptrlen = 3;
+        csubstr ssp = "foo";
+
+        {
+            SCOPED_TRACE("here 0");
+            {
+                NodeInit s(sarr);
+                node_scalar_test_foo(s.val);
+                node_scalar_test_empty(s.key);
+                s.clear();
+            }
+            {
+                NodeInit s{to_csubstr(sptr)};
+                node_scalar_test_foo(s.val);
+                node_scalar_test_empty(s.key);
+                s.clear();
+            }
+            {
+                NodeInit s{sarr};
+                node_scalar_test_foo(s.val);
+                node_scalar_test_empty(s.key);
+                s.clear();
+            }
+        }
+
+        {
+            SCOPED_TRACE("here 1");
+            {
+                NodeInit s(sarr);
+                node_scalar_test_foo(s.val);
+                node_scalar_test_empty(s.key);
+                s.clear();
+            }
+            {
+                NodeInit s(to_csubstr(sptr));
+                node_scalar_test_foo(s.val);
+                node_scalar_test_empty(s.key);
+                s.clear();
+            }
+            {
+                NodeInit s(sarr);
+                node_scalar_test_foo(s.val);
+                node_scalar_test_empty(s.key);
+                s.clear();
+            }
+        }
+
+        {
+            SCOPED_TRACE("here 2");
+            NodeInit s;
+            s = {sarr};
+            node_scalar_test_foo(s.val);
+            node_scalar_test_empty(s.key);
+            s.clear();
+            s = {to_csubstr(sptr)};
+            node_scalar_test_foo(s.val);
+            node_scalar_test_empty(s.key);
+            s.clear();
+            //s = {sptr, sptrlen}; // fails to compile
+            //node_scalar_test_foo(s.val);
+            //node_scalar_test_empty(s.key);
+            //s.clear();
+            s = {ssp};
+            node_scalar_test_foo(s.val);
+            node_scalar_test_empty(s.key);
+            s.clear();
+        }
+
+        for(auto s : {
+            NodeInit(sarr),
+            NodeInit(to_csubstr(sptr)),
+            NodeInit(csubstr{sptr, sptrlen}),
+            NodeInit(ssp)})
+        {
+            SCOPED_TRACE("here LOOP");
+            node_scalar_test_foo(s.val);
+            node_scalar_test_empty(s.key);
+        }
+    }
+
+    {
+        const char sarr[] = "foo3";
+        const char *sptr = "foo3"; size_t sptrlen = 4;
+        csubstr ssp = "foo3";
+
+        {
+            SCOPED_TRACE("here 0");
+            NodeInit s = {sarr};
+            node_scalar_test_foo3(s.val);
+            node_scalar_test_empty(s.key);
+        }
+        {   // FAILS
+            SCOPED_TRACE("here 1");
+            //NodeInit s = sarr;
+            //node_scalar_test_foo3(s.val);
+            //node_scalar_test_empty(s.key);
+        }
+        {
+            SCOPED_TRACE("here 2");
+            NodeInit s{sarr};
+            node_scalar_test_foo3(s.val);
+            node_scalar_test_empty(s.key);
+        }
+        {
+            SCOPED_TRACE("here 3");
+            NodeInit s(sarr);
+            node_scalar_test_foo3(s.val);
+            node_scalar_test_empty(s.key);
+        }
+
+        for(auto s : {
+            NodeInit(sarr),
+            NodeInit(to_csubstr(sptr)),
+            NodeInit(csubstr{sptr, sptrlen}),
+            NodeInit(ssp)})
+        {
+            SCOPED_TRACE("here LOOP");
+            node_scalar_test_foo3(s.val);
+            node_scalar_test_empty(s.key);
+        }
+    }
+}
+
+
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+
+TEST(Tree, empty_ctor)
+{
+    Tree tree;
+    EXPECT_EQ(tree.callbacks(), get_callbacks());
+    EXPECT_EQ(tree.empty(), true);
+    EXPECT_EQ(tree.capacity(), 0u);
+    EXPECT_EQ(tree.arena_capacity(), 0u);
+    EXPECT_EQ(tree.arena_slack(), 0u);
+    EXPECT_EQ(tree.size(), 0u);
+    EXPECT_EQ(tree.slack(), 0u);
+    EXPECT_EQ(tree.arena().empty(), true);
+}
+
+TEST(Tree, node_cap_ctor)
+{
+    {
+        Tree tree(10u);
+        EXPECT_EQ(tree.callbacks(), get_callbacks());
+        EXPECT_EQ(tree.empty(), false); // we have the root
+        EXPECT_EQ(tree.capacity(), 10u);
+        EXPECT_EQ(tree.arena_capacity(), 0u);
+        EXPECT_EQ(tree.arena_slack(), 0u);
+        EXPECT_EQ(tree.arena().empty(), true);
+        EXPECT_EQ(tree.size(), 1u); // we have the root
+        EXPECT_EQ(tree.slack(), 9u);
+    }
+    {
+        Tree tree(10u, 20u);
+        EXPECT_EQ(tree.callbacks(), get_callbacks());
+        EXPECT_EQ(tree.empty(), false); // we have the root
+        EXPECT_EQ(tree.capacity(), 10u);
+        EXPECT_EQ(tree.arena_capacity(), 20u);
+        EXPECT_EQ(tree.arena().empty(), true);
+        EXPECT_EQ(tree.size(), 1u); // we have the root
+        EXPECT_EQ(tree.slack(), 9u);
+    }
+    {
+        Tree tree(0u, 20u);
+        EXPECT_EQ(tree.callbacks(), get_callbacks());
+        EXPECT_EQ(tree.empty(), true);
+        EXPECT_EQ(tree.capacity(), 0u);
+        EXPECT_EQ(tree.arena_capacity(), 20u);
+        EXPECT_EQ(tree.arena_slack(), 20u);
+        EXPECT_EQ(tree.arena().empty(), true);
+        EXPECT_EQ(tree.size(), 0u);
+        EXPECT_EQ(tree.slack(), 0u);
+    }
+}
+
+Tree get_test_tree(CallbacksTester *cbt=nullptr)
+{
+    Parser parser(cbt ? cbt->callbacks() : get_callbacks());
+    Tree t = parser.parse_in_arena("", "{a: b, c: d, e: [0, 1, 2, 3]}");
+    // make sure the tree has strings in its arena
+    NodeRef n = t.rootref();
+    NodeRef ch = n.append_child();
+    ch << key("serialized_key");
+    ch << 89;
+    return t;
+}
+
+TEST(Tree, test_tree_has_arena)
+{
+    {
+        Tree t = get_test_tree();
+        ASSERT_GT(t.arena().size(), 0u);
+    }
+    {
+        CallbacksTester cbt;
+        Tree t = get_test_tree(&cbt);
+        ASSERT_GT(t.arena().size(), 0u);
+    }
+}
+
+//-------------------------------------------
+TEST(Tree, copy_ctor)
+{
+    CallbacksTester cbt;
+    {
+        Tree src = get_test_tree(&cbt);
+        test_invariants(src);
+        {
+            Tree dst(src);
+            test_invariants(dst);
+            test_compare(dst, src);
+            test_arena_not_shared(dst, src);
+            EXPECT_EQ(dst.callbacks(), src.callbacks());
+        }
+    }
+}
+
+//-------------------------------------------
+TEST(Tree, move_ctor)
+{
+    CallbacksTester cbt;
+    Tree src = get_test_tree(&cbt);
+    test_invariants(src);
+    Tree save(src);
+    test_invariants(save);
+    test_compare(save, src);
+    {
+        Tree dst(std::move(src));
+        EXPECT_EQ(src.empty(), true);
+        EXPECT_EQ(src.size(), 0u);
+        EXPECT_EQ(src.arena().empty(), true);
+        EXPECT_EQ(dst.size(), save.size());
+        EXPECT_EQ(dst.arena(), save.arena());
+        test_invariants(src);
+        test_invariants(dst);
+        test_compare(dst, save);
+        test_arena_not_shared(src, dst);
+        test_arena_not_shared(save, dst);
+    }
+}
+
+//-------------------------------------------
+TEST(Tree, copy_assign_same_callbacks)
+{
+    CallbacksTester cbt;
+    {
+        Tree src = get_test_tree(&cbt);
+        test_invariants(src);
+        {
+            Tree dst(cbt.callbacks());
+            EXPECT_EQ(dst.callbacks(), src.callbacks());
+            test_invariants(dst);
+            dst = src;
+            test_invariants(dst);
+            test_compare(dst, src);
+            test_arena_not_shared(dst, src);
+            EXPECT_EQ(dst.callbacks(), src.callbacks());
+        }
+    }
+}
+
+TEST(Tree, copy_assign_diff_callbacks)
+{
+    CallbacksTester cbsrc("src");
+    CallbacksTester cbdst("dst");
+    {
+        Tree src = get_test_tree(&cbsrc);
+        EXPECT_EQ(src.callbacks(), cbsrc.callbacks());
+        test_invariants(src);
+        {
+            Tree dst = get_test_tree(&cbdst);
+            EXPECT_EQ(dst.callbacks(), cbdst.callbacks());
+            test_invariants(dst);
+            dst = src;
+            test_invariants(dst);
+            test_compare(dst, src);
+            test_arena_not_shared(dst, src);
+            EXPECT_EQ(dst.callbacks(), src.callbacks());
+        }
+    }
+}
+
+//-------------------------------------------
+TEST(Tree, move_assign_same_callbacks)
+{
+    CallbacksTester cbt;
+    Tree src = get_test_tree(&cbt);
+    test_invariants(src);
+    Tree save(src);
+    EXPECT_EQ(save.callbacks(), src.callbacks());
+    test_invariants(save);
+    test_compare(save, src);
+    {
+        Tree dst = get_test_tree(&cbt);
+        EXPECT_NE(dst.empty(), true);
+        EXPECT_NE(dst.size(), 0u);
+        EXPECT_NE(dst.arena().empty(), true);
+        dst = std::move(src);
+        EXPECT_EQ(src.empty(), true);
+        EXPECT_EQ(src.size(), 0u);
+        EXPECT_EQ(src.arena().empty(), true);
+        EXPECT_EQ(src.callbacks(), cbt.callbacks());
+        EXPECT_EQ(dst.size(), save.size());
+        EXPECT_EQ(dst.arena(), save.arena());
+        EXPECT_EQ(dst.callbacks(), save.callbacks());
+        test_invariants(src);
+        test_invariants(dst);
+        test_compare(dst, save);
+        test_arena_not_shared(src, dst);
+        test_arena_not_shared(save, dst);
+    }
+}
+
+TEST(Tree, move_assign_diff_callbacks)
+{
+    CallbacksTester cbsrc("src");
+    CallbacksTester cbdst("dst");
+    Tree src = get_test_tree(&cbsrc);
+    test_invariants(src);
+    Tree save(src);
+    test_invariants(save);
+    test_compare(save, src);
+    {
+        Tree dst = get_test_tree(&cbdst);
+        EXPECT_NE(dst.empty(), true);
+        EXPECT_NE(dst.size(), 0u);
+        EXPECT_NE(dst.arena().empty(), true);
+        EXPECT_EQ(dst.callbacks(), cbdst.callbacks());
+        dst = std::move(src);
+        EXPECT_EQ(src.empty(), true);
+        EXPECT_EQ(src.size(), 0u);
+        EXPECT_EQ(src.arena().empty(), true);
+        EXPECT_EQ(src.callbacks(), cbsrc.callbacks());
+        EXPECT_EQ(dst.size(), save.size());
+        EXPECT_EQ(dst.arena(), save.arena());
+        EXPECT_NE(dst.callbacks(), cbdst.callbacks());
+        EXPECT_EQ(dst.callbacks(), save.callbacks());
+        test_invariants(src);
+        test_invariants(dst);
+        test_compare(dst, save);
+        test_arena_not_shared(src, dst);
+        test_arena_not_shared(save, dst);
+    }
+}
+
+TEST(Tree, std_interop)
+{
+    CallbacksTester cbt;
+    std::vector<Tree> forest;
+    for(size_t i = 0; i < 3; ++i)
+    {
+        forest.emplace_back(cbt.callbacks());
+        parse_in_arena("{foo: bar}", &forest.back());
+    }
+}
+
+
+//-------------------------------------------
+TEST(Tree, reserve)
+{
+    Tree t(16, 64);
+    EXPECT_EQ(t.capacity(), 16);
+    EXPECT_EQ(t.slack(), 15);
+    EXPECT_EQ(t.size(), 1);
+    EXPECT_EQ(t.arena_capacity(), 64);
+    EXPECT_EQ(t.arena_slack(), 64);
+    EXPECT_EQ(t.arena_size(), 0);
+    test_invariants(t);
+
+    auto buf = t.m_buf;
+    t.reserve(16);
+    t.reserve_arena(64);
+    EXPECT_EQ(t.m_buf, buf);
+    EXPECT_EQ(t.capacity(), 16);
+    EXPECT_EQ(t.slack(), 15);
+    EXPECT_EQ(t.size(), 1);
+    EXPECT_EQ(t.arena_capacity(), 64);
+    EXPECT_EQ(t.arena_slack(), 64);
+    EXPECT_EQ(t.arena_size(), 0);
+    test_invariants(t);
+
+    t.reserve(32);
+    t.reserve_arena(128);
+    EXPECT_EQ(t.capacity(), 32);
+    EXPECT_EQ(t.slack(), 31);
+    EXPECT_EQ(t.size(), 1);
+    EXPECT_EQ(t.arena_capacity(), 128);
+    EXPECT_EQ(t.arena_slack(), 128);
+    EXPECT_EQ(t.arena_size(), 0);
+    test_invariants(t);
+
+    buf = t.m_buf;
+    parse_in_arena("[a, b, c, d, e, f]", &t);
+    EXPECT_EQ(t.m_buf, buf);
+    EXPECT_EQ(t.capacity(), 32);
+    EXPECT_EQ(t.slack(), 25);
+    EXPECT_EQ(t.size(), 7);
+    EXPECT_EQ(t.arena_capacity(), 128);
+    EXPECT_EQ(t.arena_slack(), 110);
+    EXPECT_EQ(t.arena_size(), 18);
+    test_invariants(t);
+
+    t.reserve(64);
+    t.reserve_arena(256);
+    EXPECT_EQ(t.capacity(), 64);
+    EXPECT_EQ(t.slack(), 57);
+    EXPECT_EQ(t.size(), 7);
+    EXPECT_EQ(t.arena_capacity(), 256);
+    EXPECT_EQ(t.arena_slack(), 238);
+    EXPECT_EQ(t.arena_size(), 18);
+    test_invariants(t);
+}
+
+// https://github.com/biojppm/rapidyaml/issues/288
+TEST(Tree, reserve_arena_issue288)
+{
+    Tree t;
+    EXPECT_EQ(t.arena_slack(), 0u);
+    EXPECT_EQ(t.arena_capacity(), 0u);
+    EXPECT_EQ(t.arena_size(), 0u);
+    t.reserve_arena(3u);
+    EXPECT_EQ(t.arena_slack(), 3u);
+    EXPECT_GE(t.arena_capacity(), 3u);
+    EXPECT_EQ(t.arena_size(), 0u);
+    // longer than the slack to cause another call to _grow_arena()
+    std::string stars(2 * t.arena_slack(), '*');
+    t.copy_to_arena(to_csubstr(stars));
+    EXPECT_GE(t.arena_capacity(), stars.size());
+    EXPECT_EQ(t.arena_size(), stars.size());
+    EXPECT_EQ(t.arena(), to_csubstr(stars));
+    // again
+    std::string pluses(2 * t.arena_slack(), '+');
+    t.copy_to_arena(to_csubstr(pluses));
+    EXPECT_GE(t.arena_capacity(), stars.size() + pluses.size());
+    EXPECT_EQ(t.arena_size(), stars.size() + pluses.size());
+    EXPECT_EQ(t.arena().first(stars.size()), to_csubstr(stars));
+    EXPECT_EQ(t.arena().last(pluses.size()), to_csubstr(pluses));
+}
+
+TEST(Tree, clear)
+{
+    Tree t(16, 64);
+    EXPECT_EQ(t.capacity(), 16);
+    EXPECT_EQ(t.slack(), 15);
+    EXPECT_EQ(t.size(), 1);
+    EXPECT_EQ(t.arena_capacity(), 64);
+    EXPECT_EQ(t.arena_slack(), 64);
+    EXPECT_EQ(t.arena_size(), 0);
+    test_invariants(t);
+
+    t.clear();
+    t.clear_arena();
+    EXPECT_EQ(t.capacity(), 16);
+    EXPECT_EQ(t.slack(), 15);
+    EXPECT_EQ(t.size(), 1);
+    EXPECT_EQ(t.arena_capacity(), 64);
+    EXPECT_EQ(t.arena_slack(), 64);
+    EXPECT_EQ(t.arena_size(), 0);
+    test_invariants(t);
+
+    auto buf = t.m_buf;
+    t.reserve(16);
+    t.reserve_arena(64);
+    EXPECT_EQ(t.m_buf, buf);
+    EXPECT_EQ(t.capacity(), 16);
+    EXPECT_EQ(t.slack(), 15);
+    EXPECT_EQ(t.size(), 1);
+    EXPECT_EQ(t.arena_capacity(), 64);
+    EXPECT_EQ(t.arena_slack(), 64);
+    EXPECT_EQ(t.arena_size(), 0);
+    test_invariants(t);
+
+    t.reserve(32);
+    t.reserve_arena(128);
+    EXPECT_EQ(t.capacity(), 32);
+    EXPECT_EQ(t.slack(), 31);
+    EXPECT_EQ(t.size(), 1);
+    EXPECT_EQ(t.arena_capacity(), 128);
+    EXPECT_EQ(t.arena_slack(), 128);
+    EXPECT_EQ(t.arena_size(), 0);
+    test_invariants(t);
+
+    buf = t.m_buf;
+    parse_in_arena("[a, b, c, d, e, f]", &t);
+    EXPECT_EQ(t.m_buf, buf);
+    EXPECT_EQ(t.capacity(), 32);
+    EXPECT_EQ(t.slack(), 25);
+    EXPECT_EQ(t.size(), 7);
+    EXPECT_EQ(t.arena_capacity(), 128);
+    EXPECT_EQ(t.arena_slack(), 110);
+    EXPECT_EQ(t.arena_size(), 18);
+    test_invariants(t);
+
+    t.clear();
+    t.clear_arena();
+    EXPECT_EQ(t.capacity(), 32);
+    EXPECT_EQ(t.slack(), 31);
+    EXPECT_EQ(t.size(), 1);
+    EXPECT_EQ(t.arena_capacity(), 128);
+    EXPECT_EQ(t.arena_slack(), 128);
+    EXPECT_EQ(t.arena_size(), 0);
+    test_invariants(t);
+}
+
+
+//-------------------------------------------
+
+TEST(Tree, ref)
+{
+    Tree t = parse_in_arena("[0, 1, 2, 3]");
+    EXPECT_EQ(t.ref(0).id(), 0);
+    EXPECT_EQ(t.ref(1).id(), 1);
+    EXPECT_EQ(t.ref(2).id(), 2);
+    EXPECT_EQ(t.ref(3).id(), 3);
+    EXPECT_EQ(t.ref(4).id(), 4);
+    EXPECT_TRUE(t.ref(0).is_seq());
+    EXPECT_TRUE(t.ref(1).is_val());
+    EXPECT_TRUE(t.ref(2).is_val());
+    EXPECT_TRUE(t.ref(3).is_val());
+    EXPECT_TRUE(t.ref(4).is_val());
+}
+
+TEST(Tree, ref_const)
+{
+    const Tree t = parse_in_arena("[0, 1, 2, 3]");
+    EXPECT_EQ(t.ref(0).id(), 0);
+    EXPECT_EQ(t.ref(1).id(), 1);
+    EXPECT_EQ(t.ref(2).id(), 2);
+    EXPECT_EQ(t.ref(3).id(), 3);
+    EXPECT_EQ(t.ref(4).id(), 4);
+    EXPECT_TRUE(t.ref(0).is_seq());
+    EXPECT_TRUE(t.ref(1).is_val());
+    EXPECT_TRUE(t.ref(2).is_val());
+    EXPECT_TRUE(t.ref(3).is_val());
+    EXPECT_TRUE(t.ref(4).is_val());
+}
+
+
+TEST(Tree, operator_square_brackets)
+{
+    {
+        Tree t = parse_in_arena("[0, 1, 2, 3, 4]");
+        Tree &m = t;
+        Tree const& cm = t;
+        EXPECT_EQ(m[0].val(), "0");
+        EXPECT_EQ(m[1].val(), "1");
+        EXPECT_EQ(m[2].val(), "2");
+        EXPECT_EQ(m[3].val(), "3");
+        EXPECT_EQ(m[4].val(), "4");
+        EXPECT_EQ(cm[0].val(), "0");
+        EXPECT_EQ(cm[1].val(), "1");
+        EXPECT_EQ(cm[2].val(), "2");
+        EXPECT_EQ(cm[3].val(), "3");
+        EXPECT_EQ(cm[4].val(), "4");
+        //
+        EXPECT_TRUE(m[0]  == "0");
+        EXPECT_TRUE(m[1]  == "1");
+        EXPECT_TRUE(m[2]  == "2");
+        EXPECT_TRUE(m[3]  == "3");
+        EXPECT_TRUE(m[4]  == "4");
+        EXPECT_TRUE(cm[0] == "0");
+        EXPECT_TRUE(cm[1] == "1");
+        EXPECT_TRUE(cm[2] == "2");
+        EXPECT_TRUE(cm[3] == "3");
+        EXPECT_TRUE(cm[4] == "4");
+        //
+        EXPECT_FALSE(m[0]  != "0");
+        EXPECT_FALSE(m[1]  != "1");
+        EXPECT_FALSE(m[2]  != "2");
+        EXPECT_FALSE(m[3]  != "3");
+        EXPECT_FALSE(m[4]  != "4");
+        EXPECT_FALSE(cm[0] != "0");
+        EXPECT_FALSE(cm[1] != "1");
+        EXPECT_FALSE(cm[2] != "2");
+        EXPECT_FALSE(cm[3] != "3");
+        EXPECT_FALSE(cm[4] != "4");
+    }
+    {
+        Tree t = parse_in_arena("{a: 0, b: 1, c: 2, d: 3, e: 4}");
+        Tree &m = t;
+        Tree const& cm = t;
+        EXPECT_EQ(m["a"].val(), "0");
+        EXPECT_EQ(m["b"].val(), "1");
+        EXPECT_EQ(m["c"].val(), "2");
+        EXPECT_EQ(m["d"].val(), "3");
+        EXPECT_EQ(m["e"].val(), "4");
+        EXPECT_EQ(cm["a"].val(), "0");
+        EXPECT_EQ(cm["b"].val(), "1");
+        EXPECT_EQ(cm["c"].val(), "2");
+        EXPECT_EQ(cm["d"].val(), "3");
+        EXPECT_EQ(cm["e"].val(), "4");
+        //
+        EXPECT_TRUE(m["a"] == "0");
+        EXPECT_TRUE(m["b"] == "1");
+        EXPECT_TRUE(m["c"] == "2");
+        EXPECT_TRUE(m["d"] == "3");
+        EXPECT_TRUE(m["e"] == "4");
+        EXPECT_TRUE(cm["a"] == "0");
+        EXPECT_TRUE(cm["b"] == "1");
+        EXPECT_TRUE(cm["c"] == "2");
+        EXPECT_TRUE(cm["d"] == "3");
+        EXPECT_TRUE(cm["e"] == "4");
+        //
+        EXPECT_FALSE(m["a"] != "0");
+        EXPECT_FALSE(m["b"] != "1");
+        EXPECT_FALSE(m["c"] != "2");
+        EXPECT_FALSE(m["d"] != "3");
+        EXPECT_FALSE(m["e"] != "4");
+        EXPECT_FALSE(cm["a"] != "0");
+        EXPECT_FALSE(cm["b"] != "1");
+        EXPECT_FALSE(cm["c"] != "2");
+        EXPECT_FALSE(cm["d"] != "3");
+        EXPECT_FALSE(cm["e"] != "4");
+    }
+}
+
+TEST(Tree, relocate)
+{
+    // create a tree with anchors and refs, and copy it to ensure the
+    // relocation also applies to the anchors and refs. Ensure to put
+    // the source in the arena so that it gets relocated.
+    Tree tree = parse_in_arena(R"(&keyanchor key: val
+key2: &valanchor val2
+keyref: *keyanchor
+*valanchor: was val anchor
+!!int 0: !!str foo
+!!str doe: !!str a deer a female deer
+ray: a drop of golden sun
+me: a name I call myself
+far: a long long way to run
+)");
+    Tree copy = tree;
+    EXPECT_EQ(copy.size(), tree.size());
+    EXPECT_EQ(emitrs_yaml<std::string>(copy), R"(&keyanchor key: val
+key2: &valanchor val2
+keyref: *keyanchor
+*valanchor: was val anchor
+!!int 0: !!str foo
+!!str doe: !!str a deer a female deer
+ray: a drop of golden sun
+me: a name I call myself
+far: a long long way to run
+)");
+    //
+    Tree copy2 = copy;
+    EXPECT_EQ(copy.size(), tree.size());
+    copy2.resolve();
+    EXPECT_EQ(emitrs_yaml<std::string>(copy2), R"(key: val
+key2: val2
+keyref: key
+val2: was val anchor
+!!int 0: !!str foo
+!!str doe: !!str a deer a female deer
+ray: a drop of golden sun
+me: a name I call myself
+far: a long long way to run
+)");
+}
+
+
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+
+TEST(NodeType, type_str)
+{
+    // avoid coverage misses
+    EXPECT_EQ(to_csubstr(NodeType(KEYVAL).type_str()), "KEYVAL");
+    EXPECT_EQ(to_csubstr(NodeType(KEY).type_str()), "KEY");
+    EXPECT_EQ(to_csubstr(NodeType(VAL).type_str()), "VAL");
+    EXPECT_EQ(to_csubstr(NodeType(MAP).type_str()), "MAP");
+    EXPECT_EQ(to_csubstr(NodeType(SEQ).type_str()), "SEQ");
+    EXPECT_EQ(to_csubstr(NodeType(KEYMAP).type_str()), "KEYMAP");
+    EXPECT_EQ(to_csubstr(NodeType(KEYSEQ).type_str()), "KEYSEQ");
+    EXPECT_EQ(to_csubstr(NodeType(DOCSEQ).type_str()), "DOCSEQ");
+    EXPECT_EQ(to_csubstr(NodeType(DOCMAP).type_str()), "DOCMAP");
+    EXPECT_EQ(to_csubstr(NodeType(DOCVAL).type_str()), "DOCVAL");
+    EXPECT_EQ(to_csubstr(NodeType(DOC).type_str()), "DOC");
+    EXPECT_EQ(to_csubstr(NodeType(STREAM).type_str()), "STREAM");
+    EXPECT_EQ(to_csubstr(NodeType(NOTYPE).type_str()), "NOTYPE");
+    EXPECT_EQ(to_csubstr(NodeType(KEYVAL|KEYREF).type_str()), "KEYVAL***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYVAL|VALREF).type_str()), "KEYVAL***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYVAL|KEYANCH).type_str()), "KEYVAL***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYVAL|VALANCH).type_str()), "KEYVAL***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYVAL|KEYREF|VALANCH).type_str()), "KEYVAL***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYVAL|KEYANCH|VALREF).type_str()), "KEYVAL***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYMAP|KEYREF).type_str()), "KEYMAP***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYMAP|VALREF).type_str()), "KEYMAP***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYMAP|KEYANCH).type_str()), "KEYMAP***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYMAP|VALANCH).type_str()), "KEYMAP***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYMAP|KEYREF|VALANCH).type_str()), "KEYMAP***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYMAP|KEYANCH|VALREF).type_str()), "KEYMAP***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYSEQ|KEYREF).type_str()), "KEYSEQ***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYSEQ|VALREF).type_str()), "KEYSEQ***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYSEQ|KEYANCH).type_str()), "KEYSEQ***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYSEQ|VALANCH).type_str()), "KEYSEQ***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYSEQ|KEYREF|VALANCH).type_str()), "KEYSEQ***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYSEQ|KEYANCH|VALREF).type_str()), "KEYSEQ***");
+    EXPECT_EQ(to_csubstr(NodeType(DOCSEQ|VALANCH).type_str()), "DOCSEQ***");
+    EXPECT_EQ(to_csubstr(NodeType(DOCSEQ|VALREF).type_str()), "DOCSEQ***");
+    EXPECT_EQ(to_csubstr(NodeType(DOCMAP|VALANCH).type_str()), "DOCMAP***");
+    EXPECT_EQ(to_csubstr(NodeType(DOCMAP|VALREF).type_str()), "DOCMAP***");
+    EXPECT_EQ(to_csubstr(NodeType(DOCVAL|VALANCH).type_str()), "DOCVAL***");
+    EXPECT_EQ(to_csubstr(NodeType(DOCVAL|VALREF).type_str()), "DOCVAL***");
+    EXPECT_EQ(to_csubstr(NodeType(KEY|KEYREF).type_str()), "KEY***");
+    EXPECT_EQ(to_csubstr(NodeType(KEY|KEYANCH).type_str()), "KEY***");
+    EXPECT_EQ(to_csubstr(NodeType(VAL|VALREF).type_str()), "VAL***");
+    EXPECT_EQ(to_csubstr(NodeType(VAL|VALANCH).type_str()), "VAL***");
+    EXPECT_EQ(to_csubstr(NodeType(MAP|VALREF).type_str()), "MAP***");
+    EXPECT_EQ(to_csubstr(NodeType(MAP|VALANCH).type_str()), "MAP***");
+    EXPECT_EQ(to_csubstr(NodeType(SEQ|VALREF).type_str()), "SEQ***");
+    EXPECT_EQ(to_csubstr(NodeType(SEQ|VALANCH).type_str()), "SEQ***");
+    EXPECT_EQ(to_csubstr(NodeType(DOC|VALREF).type_str()), "DOC***");
+    EXPECT_EQ(to_csubstr(NodeType(DOC|VALANCH).type_str()), "DOC***");
+    EXPECT_EQ(to_csubstr(NodeType(KEYREF).type_str()), "(unk)");
+    EXPECT_EQ(to_csubstr(NodeType(VALREF).type_str()), "(unk)");
+    EXPECT_EQ(to_csubstr(NodeType(KEYANCH).type_str()), "(unk)");
+    EXPECT_EQ(to_csubstr(NodeType(VALANCH).type_str()), "(unk)");
+}
+
+TEST(NodeType, is_stream)
+{
+    EXPECT_FALSE(NodeType(NOTYPE).is_stream());
+    EXPECT_TRUE(NodeType(STREAM).is_stream());
+}
+
+TEST(Tree, is_stream)
+{
+    Tree t = parse_in_arena(R"(---
+foo: bar
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t keyval_id = t.first_child(doc_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    EXPECT_TRUE(t.is_stream(stream_id));
+    EXPECT_FALSE(t.is_stream(doc_id));
+    EXPECT_FALSE(t.is_stream(keyval_id));
+    EXPECT_TRUE(stream.is_stream());
+    EXPECT_FALSE(doc.is_stream());
+    EXPECT_FALSE(keyval.is_stream());
+    EXPECT_EQ(t.is_stream(stream_id), t._p(stream_id)->m_type.is_stream());
+    EXPECT_EQ(t.is_stream(doc_id), t._p(doc_id)->m_type.is_stream());
+    EXPECT_EQ(t.is_stream(keyval_id), t._p(keyval_id)->m_type.is_stream());
+    EXPECT_EQ(stream.is_stream(), stream.get()->m_type.is_stream());
+    EXPECT_EQ(doc.is_stream(), doc.get()->m_type.is_stream());
+    EXPECT_EQ(keyval.is_stream(), keyval.get()->m_type.is_stream());
+}
+
+TEST(NodeType, is_doc)
+{
+    EXPECT_FALSE(NodeType(NOTYPE).is_doc());
+    EXPECT_TRUE(NodeType(DOC).is_doc());
+}
+
+TEST(Tree, is_doc)
+{
+    Tree t = parse_in_arena(R"(---
+foo: bar
+---
+a scalar
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t keyval_id = t.first_child(doc_id);
+    const size_t docval_id = t.last_child(stream_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef docval = t.ref(docval_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mdocval = t.ref(docval_id);
+    EXPECT_FALSE(t.is_doc(stream_id));
+    EXPECT_TRUE(t.is_doc(doc_id));
+    EXPECT_FALSE(t.is_doc(keyval_id));
+    EXPECT_TRUE(t.is_doc(docval_id));
+    EXPECT_FALSE(stream.is_doc());
+    EXPECT_TRUE(doc.is_doc());
+    EXPECT_FALSE(keyval.is_doc());
+    EXPECT_TRUE(docval.is_doc());
+    EXPECT_FALSE(mstream.is_doc());
+    EXPECT_TRUE(mdoc.is_doc());
+    EXPECT_FALSE(mkeyval.is_doc());
+    EXPECT_TRUE(mdocval.is_doc());
+    EXPECT_EQ(t.is_doc(stream_id), t._p(stream_id)->m_type.is_doc());
+    EXPECT_EQ(t.is_doc(doc_id), t._p(doc_id)->m_type.is_doc());
+    EXPECT_EQ(t.is_doc(keyval_id), t._p(keyval_id)->m_type.is_doc());
+    EXPECT_EQ(t.is_doc(docval_id), t._p(docval_id)->m_type.is_doc());
+    EXPECT_EQ(stream.is_doc(), stream.get()->m_type.is_doc());
+    EXPECT_EQ(doc.is_doc(), doc.get()->m_type.is_doc());
+    EXPECT_EQ(keyval.is_doc(), keyval.get()->m_type.is_doc());
+    EXPECT_EQ(docval.is_doc(), docval.get()->m_type.is_doc());
+    EXPECT_EQ(mstream.is_doc(), mstream.get()->m_type.is_doc());
+    EXPECT_EQ(mdoc.is_doc(), mdoc.get()->m_type.is_doc());
+    EXPECT_EQ(mkeyval.is_doc(), mkeyval.get()->m_type.is_doc());
+    EXPECT_EQ(mdocval.is_doc(), mdocval.get()->m_type.is_doc());
+}
+
+TEST(NodeType, is_container)
+{
+    EXPECT_FALSE(NodeType(NOTYPE).is_container());
+    EXPECT_FALSE(NodeType(VAL).is_container());
+    EXPECT_FALSE(NodeType(KEY).is_container());
+    EXPECT_FALSE(NodeType(KEYVAL).is_container());
+    EXPECT_TRUE(NodeType(MAP).is_container());
+    EXPECT_TRUE(NodeType(SEQ).is_container());
+    EXPECT_TRUE(NodeType(KEYMAP).is_container());
+    EXPECT_TRUE(NodeType(KEYSEQ).is_container());
+    EXPECT_TRUE(NodeType(DOCMAP).is_container());
+    EXPECT_TRUE(NodeType(DOCSEQ).is_container());
+}
+
+TEST(Tree, is_container)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: bar}
+seq: [foo, bar]
+---
+a scalar
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t docval_id = t.last_child(stream_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef docval = t.ref(docval_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mdocval = t.ref(docval_id);
+    EXPECT_TRUE(t.is_container(stream_id));
+    EXPECT_TRUE(t.is_container(doc_id));
+    EXPECT_TRUE(t.is_container(map_id));
+    EXPECT_FALSE(t.is_container(keyval_id));
+    EXPECT_TRUE(t.is_container(seq_id));
+    EXPECT_FALSE(t.is_container(val_id));
+    EXPECT_FALSE(t.is_container(docval_id));
+    EXPECT_TRUE(stream.is_container());
+    EXPECT_TRUE(doc.is_container());
+    EXPECT_TRUE(map.is_container());
+    EXPECT_FALSE(keyval.is_container());
+    EXPECT_TRUE(seq.is_container());
+    EXPECT_FALSE(val.is_container());
+    EXPECT_FALSE(docval.is_container());
+    EXPECT_TRUE(mstream.is_container());
+    EXPECT_TRUE(mdoc.is_container());
+    EXPECT_TRUE(mmap.is_container());
+    EXPECT_FALSE(mkeyval.is_container());
+    EXPECT_TRUE(mseq.is_container());
+    EXPECT_FALSE(mval.is_container());
+    EXPECT_FALSE(mdocval.is_container());
+    EXPECT_EQ(t.is_container(stream_id), t._p(stream_id)->m_type.is_container());
+    EXPECT_EQ(t.is_container(doc_id), t._p(doc_id)->m_type.is_container());
+    EXPECT_EQ(t.is_container(map_id), t._p(map_id)->m_type.is_container());
+    EXPECT_EQ(t.is_container(keyval_id), t._p(keyval_id)->m_type.is_container());
+    EXPECT_EQ(t.is_container(seq_id), t._p(seq_id)->m_type.is_container());
+    EXPECT_EQ(t.is_container(val_id), t._p(val_id)->m_type.is_container());
+    EXPECT_EQ(t.is_container(docval_id), t._p(docval_id)->m_type.is_container());
+    EXPECT_EQ(stream.is_container(), stream.get()->m_type.is_container());
+    EXPECT_EQ(doc.is_container(), doc.get()->m_type.is_container());
+    EXPECT_EQ(map.is_container(), map.get()->m_type.is_container());
+    EXPECT_EQ(keyval.is_container(), keyval.get()->m_type.is_container());
+    EXPECT_EQ(seq.is_container(), seq.get()->m_type.is_container());
+    EXPECT_EQ(val.is_container(), val.get()->m_type.is_container());
+    EXPECT_EQ(docval.is_container(), docval.get()->m_type.is_container());
+    EXPECT_EQ(mstream.is_container(), mstream.get()->m_type.is_container());
+    EXPECT_EQ(mdoc.is_container(), mdoc.get()->m_type.is_container());
+    EXPECT_EQ(mmap.is_container(), mmap.get()->m_type.is_container());
+    EXPECT_EQ(mkeyval.is_container(), mkeyval.get()->m_type.is_container());
+    EXPECT_EQ(mseq.is_container(), mseq.get()->m_type.is_container());
+    EXPECT_EQ(mval.is_container(), mval.get()->m_type.is_container());
+    EXPECT_EQ(mdocval.is_container(), mdocval.get()->m_type.is_container());
+}
+
+TEST(NodeType, is_map)
+{
+    EXPECT_FALSE(NodeType(NOTYPE).is_map());
+    EXPECT_FALSE(NodeType(VAL).is_map());
+    EXPECT_FALSE(NodeType(KEY).is_map());
+    EXPECT_TRUE(NodeType(MAP).is_map());
+    EXPECT_TRUE(NodeType(KEYMAP).is_map());
+    EXPECT_FALSE(NodeType(SEQ).is_map());
+    EXPECT_FALSE(NodeType(KEYSEQ).is_map());
+}
+
+TEST(Tree, is_map)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: bar}
+seq: [foo, bar]
+---
+a scalar
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t docval_id = t.last_child(stream_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef docval = t.ref(docval_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mdocval = t.ref(docval_id);
+    EXPECT_FALSE(t.is_map(stream_id));
+    EXPECT_TRUE(t.is_map(doc_id));
+    EXPECT_TRUE(t.is_map(map_id));
+    EXPECT_FALSE(t.is_map(keyval_id));
+    EXPECT_FALSE(t.is_map(seq_id));
+    EXPECT_FALSE(t.is_map(val_id));
+    EXPECT_FALSE(t.is_map(docval_id));
+    EXPECT_FALSE(stream.is_map());
+    EXPECT_TRUE(doc.is_map());
+    EXPECT_TRUE(map.is_map());
+    EXPECT_FALSE(keyval.is_map());
+    EXPECT_FALSE(seq.is_map());
+    EXPECT_FALSE(val.is_map());
+    EXPECT_FALSE(docval.is_map());
+    EXPECT_FALSE(mstream.is_map());
+    EXPECT_TRUE(mdoc.is_map());
+    EXPECT_TRUE(mmap.is_map());
+    EXPECT_FALSE(mkeyval.is_map());
+    EXPECT_FALSE(mseq.is_map());
+    EXPECT_FALSE(mval.is_map());
+    EXPECT_FALSE(mdocval.is_map());
+    EXPECT_EQ(t.is_map(stream_id), t._p(stream_id)->m_type.is_map());
+    EXPECT_EQ(t.is_map(doc_id), t._p(doc_id)->m_type.is_map());
+    EXPECT_EQ(t.is_map(map_id), t._p(map_id)->m_type.is_map());
+    EXPECT_EQ(t.is_map(keyval_id), t._p(keyval_id)->m_type.is_map());
+    EXPECT_EQ(t.is_map(seq_id), t._p(seq_id)->m_type.is_map());
+    EXPECT_EQ(t.is_map(val_id), t._p(val_id)->m_type.is_map());
+    EXPECT_EQ(t.is_map(docval_id), t._p(docval_id)->m_type.is_map());
+    EXPECT_EQ(stream.is_map(), stream.get()->m_type.is_map());
+    EXPECT_EQ(doc.is_map(), doc.get()->m_type.is_map());
+    EXPECT_EQ(map.is_map(), map.get()->m_type.is_map());
+    EXPECT_EQ(keyval.is_map(), keyval.get()->m_type.is_map());
+    EXPECT_EQ(seq.is_map(), seq.get()->m_type.is_map());
+    EXPECT_EQ(val.is_map(), val.get()->m_type.is_map());
+    EXPECT_EQ(docval.is_map(), docval.get()->m_type.is_map());
+    EXPECT_EQ(mstream.is_map(), mstream.get()->m_type.is_map());
+    EXPECT_EQ(mdoc.is_map(), mdoc.get()->m_type.is_map());
+    EXPECT_EQ(mmap.is_map(), mmap.get()->m_type.is_map());
+    EXPECT_EQ(mkeyval.is_map(), mkeyval.get()->m_type.is_map());
+    EXPECT_EQ(mseq.is_map(), mseq.get()->m_type.is_map());
+    EXPECT_EQ(mval.is_map(), mval.get()->m_type.is_map());
+    EXPECT_EQ(mdocval.is_map(), mdocval.get()->m_type.is_map());
+}
+
+TEST(NodeType, is_seq)
+{
+    EXPECT_FALSE(NodeType(NOTYPE).is_seq());
+    EXPECT_FALSE(NodeType(VAL).is_seq());
+    EXPECT_FALSE(NodeType(KEY).is_seq());
+    EXPECT_FALSE(NodeType(MAP).is_seq());
+    EXPECT_FALSE(NodeType(KEYMAP).is_seq());
+    EXPECT_TRUE(NodeType(SEQ).is_seq());
+    EXPECT_TRUE(NodeType(KEYSEQ).is_seq());
+}
+
+TEST(Tree, is_seq)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: bar}
+seq: [foo, bar]
+---
+a scalar
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t docval_id = t.last_child(stream_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef docval = t.ref(docval_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mdocval = t.ref(docval_id);
+    EXPECT_TRUE(t.is_seq(stream_id));
+    EXPECT_FALSE(t.is_seq(doc_id));
+    EXPECT_FALSE(t.is_seq(map_id));
+    EXPECT_FALSE(t.is_seq(keyval_id));
+    EXPECT_TRUE(t.is_seq(seq_id));
+    EXPECT_FALSE(t.is_seq(val_id));
+    EXPECT_FALSE(t.is_seq(docval_id));
+    EXPECT_TRUE(stream.is_seq());
+    EXPECT_FALSE(doc.is_seq());
+    EXPECT_FALSE(map.is_seq());
+    EXPECT_FALSE(keyval.is_seq());
+    EXPECT_TRUE(seq.is_seq());
+    EXPECT_FALSE(val.is_seq());
+    EXPECT_FALSE(docval.is_seq());
+    EXPECT_TRUE(mstream.is_seq());
+    EXPECT_FALSE(mdoc.is_seq());
+    EXPECT_FALSE(mmap.is_seq());
+    EXPECT_FALSE(mkeyval.is_seq());
+    EXPECT_TRUE(mseq.is_seq());
+    EXPECT_FALSE(mval.is_seq());
+    EXPECT_FALSE(mdocval.is_seq());
+    EXPECT_EQ(t.is_seq(stream_id), t._p(stream_id)->m_type.is_seq());
+    EXPECT_EQ(t.is_seq(doc_id), t._p(doc_id)->m_type.is_seq());
+    EXPECT_EQ(t.is_seq(map_id), t._p(map_id)->m_type.is_seq());
+    EXPECT_EQ(t.is_seq(keyval_id), t._p(keyval_id)->m_type.is_seq());
+    EXPECT_EQ(t.is_seq(seq_id), t._p(seq_id)->m_type.is_seq());
+    EXPECT_EQ(t.is_seq(val_id), t._p(val_id)->m_type.is_seq());
+    EXPECT_EQ(t.is_seq(docval_id), t._p(docval_id)->m_type.is_seq());
+    EXPECT_EQ(stream.is_seq(), stream.get()->m_type.is_seq());
+    EXPECT_EQ(doc.is_seq(), doc.get()->m_type.is_seq());
+    EXPECT_EQ(map.is_seq(), map.get()->m_type.is_seq());
+    EXPECT_EQ(keyval.is_seq(), keyval.get()->m_type.is_seq());
+    EXPECT_EQ(seq.is_seq(), seq.get()->m_type.is_seq());
+    EXPECT_EQ(val.is_seq(), val.get()->m_type.is_seq());
+    EXPECT_EQ(docval.is_seq(), docval.get()->m_type.is_seq());
+    EXPECT_EQ(mstream.is_seq(), mstream.get()->m_type.is_seq());
+    EXPECT_EQ(mdoc.is_seq(), mdoc.get()->m_type.is_seq());
+    EXPECT_EQ(mmap.is_seq(), mmap.get()->m_type.is_seq());
+    EXPECT_EQ(mkeyval.is_seq(), mkeyval.get()->m_type.is_seq());
+    EXPECT_EQ(mseq.is_seq(), mseq.get()->m_type.is_seq());
+    EXPECT_EQ(mval.is_seq(), mval.get()->m_type.is_seq());
+    EXPECT_EQ(mdocval.is_seq(), mdocval.get()->m_type.is_seq());
+}
+
+TEST(NodeType, has_val)
+{
+    EXPECT_FALSE(NodeType(NOTYPE).has_val());
+    EXPECT_FALSE(NodeType(KEY).has_val());
+    EXPECT_TRUE(NodeType(VAL).has_val());
+    EXPECT_TRUE(NodeType(DOCVAL).has_val());
+    EXPECT_TRUE(NodeType(KEYVAL).has_val());
+    EXPECT_FALSE(NodeType(KEYMAP).has_val());
+    EXPECT_FALSE(NodeType(KEYSEQ).has_val());
+}
+
+TEST(Tree, has_val)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: bar}
+seq: [foo, bar]
+---
+a scalar
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t docval_id = t.last_child(stream_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef docval = t.ref(docval_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mdocval = t.ref(docval_id);
+    EXPECT_FALSE(t.has_val(stream_id));
+    EXPECT_FALSE(t.has_val(doc_id));
+    EXPECT_FALSE(t.has_val(map_id));
+    EXPECT_TRUE(t.has_val(keyval_id));
+    EXPECT_FALSE(t.has_val(seq_id));
+    EXPECT_TRUE(t.has_val(val_id));
+    EXPECT_TRUE(t.has_val(docval_id));
+    EXPECT_FALSE(stream.has_val());
+    EXPECT_FALSE(doc.has_val());
+    EXPECT_FALSE(map.has_val());
+    EXPECT_TRUE(keyval.has_val());
+    EXPECT_FALSE(seq.has_val());
+    EXPECT_TRUE(val.has_val());
+    EXPECT_TRUE(docval.has_val());
+    EXPECT_FALSE(mstream.has_val());
+    EXPECT_FALSE(mdoc.has_val());
+    EXPECT_FALSE(mmap.has_val());
+    EXPECT_TRUE(mkeyval.has_val());
+    EXPECT_FALSE(mseq.has_val());
+    EXPECT_TRUE(mval.has_val());
+    EXPECT_TRUE(mdocval.has_val());
+    EXPECT_EQ(t.has_val(stream_id), t._p(stream_id)->m_type.has_val());
+    EXPECT_EQ(t.has_val(doc_id), t._p(doc_id)->m_type.has_val());
+    EXPECT_EQ(t.has_val(map_id), t._p(map_id)->m_type.has_val());
+    EXPECT_EQ(t.has_val(keyval_id), t._p(keyval_id)->m_type.has_val());
+    EXPECT_EQ(t.has_val(seq_id), t._p(seq_id)->m_type.has_val());
+    EXPECT_EQ(t.has_val(val_id), t._p(val_id)->m_type.has_val());
+    EXPECT_EQ(t.has_val(docval_id), t._p(docval_id)->m_type.has_val());
+    EXPECT_EQ(stream.has_val(), stream.get()->m_type.has_val());
+    EXPECT_EQ(doc.has_val(), doc.get()->m_type.has_val());
+    EXPECT_EQ(map.has_val(), map.get()->m_type.has_val());
+    EXPECT_EQ(keyval.has_val(), keyval.get()->m_type.has_val());
+    EXPECT_EQ(seq.has_val(), seq.get()->m_type.has_val());
+    EXPECT_EQ(val.has_val(), val.get()->m_type.has_val());
+    EXPECT_EQ(docval.has_val(), docval.get()->m_type.has_val());
+    EXPECT_EQ(mstream.has_val(), mstream.get()->m_type.has_val());
+    EXPECT_EQ(mdoc.has_val(), mdoc.get()->m_type.has_val());
+    EXPECT_EQ(mmap.has_val(), mmap.get()->m_type.has_val());
+    EXPECT_EQ(mkeyval.has_val(), mkeyval.get()->m_type.has_val());
+    EXPECT_EQ(mseq.has_val(), mseq.get()->m_type.has_val());
+    EXPECT_EQ(mval.has_val(), mval.get()->m_type.has_val());
+    EXPECT_EQ(mdocval.has_val(), mdocval.get()->m_type.has_val());
+}
+
+TEST(NodeType, is_val)
+{
+    EXPECT_FALSE(NodeType(NOTYPE).is_val());
+    EXPECT_FALSE(NodeType(KEY).is_val());
+    EXPECT_TRUE(NodeType(VAL).is_val());
+    EXPECT_TRUE(NodeType(DOCVAL).is_val());
+    EXPECT_FALSE(NodeType(KEYVAL).is_val());
+    EXPECT_FALSE(NodeType(KEYMAP).is_val());
+    EXPECT_FALSE(NodeType(KEYSEQ).is_val());
+}
+
+TEST(Tree, is_val)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: bar}
+seq: [foo, bar]
+---
+a scalar
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t docval_id = t.last_child(stream_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef docval = t.ref(docval_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mdocval = t.ref(docval_id);
+    EXPECT_FALSE(t.is_val(stream_id));
+    EXPECT_FALSE(t.is_val(doc_id));
+    EXPECT_FALSE(t.is_val(map_id));
+    EXPECT_FALSE(t.is_val(keyval_id));
+    EXPECT_FALSE(t.is_val(seq_id));
+    EXPECT_TRUE(t.is_val(val_id));
+    EXPECT_TRUE(t.is_val(docval_id));
+    EXPECT_FALSE(stream.is_val());
+    EXPECT_FALSE(doc.is_val());
+    EXPECT_FALSE(map.is_val());
+    EXPECT_FALSE(keyval.is_val());
+    EXPECT_FALSE(seq.is_val());
+    EXPECT_TRUE(val.is_val());
+    EXPECT_TRUE(docval.is_val());
+    EXPECT_FALSE(mstream.is_val());
+    EXPECT_FALSE(mdoc.is_val());
+    EXPECT_FALSE(mmap.is_val());
+    EXPECT_FALSE(mkeyval.is_val());
+    EXPECT_FALSE(mseq.is_val());
+    EXPECT_TRUE(mval.is_val());
+    EXPECT_TRUE(mdocval.is_val());
+    EXPECT_EQ(t.is_val(stream_id), t._p(stream_id)->m_type.is_val());
+    EXPECT_EQ(t.is_val(doc_id), t._p(doc_id)->m_type.is_val());
+    EXPECT_EQ(t.is_val(map_id), t._p(map_id)->m_type.is_val());
+    EXPECT_EQ(t.is_val(keyval_id), t._p(keyval_id)->m_type.is_val());
+    EXPECT_EQ(t.is_val(seq_id), t._p(seq_id)->m_type.is_val());
+    EXPECT_EQ(t.is_val(val_id), t._p(val_id)->m_type.is_val());
+    EXPECT_EQ(t.is_val(docval_id), t._p(docval_id)->m_type.is_val());
+    EXPECT_EQ(stream.is_val(), stream.get()->m_type.is_val());
+    EXPECT_EQ(doc.is_val(), doc.get()->m_type.is_val());
+    EXPECT_EQ(map.is_val(), map.get()->m_type.is_val());
+    EXPECT_EQ(keyval.is_val(), keyval.get()->m_type.is_val());
+    EXPECT_EQ(seq.is_val(), seq.get()->m_type.is_val());
+    EXPECT_EQ(val.is_val(), val.get()->m_type.is_val());
+    EXPECT_EQ(docval.is_val(), docval.get()->m_type.is_val());
+    EXPECT_EQ(mstream.is_val(), mstream.get()->m_type.is_val());
+    EXPECT_EQ(mdoc.is_val(), mdoc.get()->m_type.is_val());
+    EXPECT_EQ(mmap.is_val(), mmap.get()->m_type.is_val());
+    EXPECT_EQ(mkeyval.is_val(), mkeyval.get()->m_type.is_val());
+    EXPECT_EQ(mseq.is_val(), mseq.get()->m_type.is_val());
+    EXPECT_EQ(mval.is_val(), mval.get()->m_type.is_val());
+    EXPECT_EQ(mdocval.is_val(), mdocval.get()->m_type.is_val());
+}
+
+TEST(NodeType, has_key)
+{
+    EXPECT_FALSE(NodeType(NOTYPE).has_key());
+    EXPECT_TRUE(NodeType(KEY).has_key());
+    EXPECT_FALSE(NodeType(VAL).has_key());
+    EXPECT_TRUE(NodeType(KEYVAL).has_key());
+    EXPECT_TRUE(NodeType(KEYMAP).has_key());
+    EXPECT_TRUE(NodeType(KEYSEQ).has_key());
+}
+
+TEST(Tree, has_key)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: bar}
+seq: [foo, bar]
+---
+a scalar
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t docval_id = t.last_child(stream_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef docval = t.ref(docval_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mdocval = t.ref(docval_id);
+    EXPECT_FALSE(t.has_key(stream_id));
+    EXPECT_FALSE(t.has_key(doc_id));
+    EXPECT_TRUE(t.has_key(map_id));
+    EXPECT_TRUE(t.has_key(keyval_id));
+    EXPECT_TRUE(t.has_key(seq_id));
+    EXPECT_FALSE(t.has_key(val_id));
+    EXPECT_FALSE(t.has_key(docval_id));
+    EXPECT_FALSE(stream.has_key());
+    EXPECT_FALSE(doc.has_key());
+    EXPECT_TRUE(map.has_key());
+    EXPECT_TRUE(keyval.has_key());
+    EXPECT_TRUE(seq.has_key());
+    EXPECT_FALSE(val.has_key());
+    EXPECT_FALSE(docval.has_key());
+    EXPECT_FALSE(mstream.has_key());
+    EXPECT_FALSE(mdoc.has_key());
+    EXPECT_TRUE(mmap.has_key());
+    EXPECT_TRUE(mkeyval.has_key());
+    EXPECT_TRUE(mseq.has_key());
+    EXPECT_FALSE(mval.has_key());
+    EXPECT_FALSE(mdocval.has_key());
+    EXPECT_EQ(t.has_key(stream_id), t._p(stream_id)->m_type.has_key());
+    EXPECT_EQ(t.has_key(doc_id), t._p(doc_id)->m_type.has_key());
+    EXPECT_EQ(t.has_key(map_id), t._p(map_id)->m_type.has_key());
+    EXPECT_EQ(t.has_key(keyval_id), t._p(keyval_id)->m_type.has_key());
+    EXPECT_EQ(t.has_key(seq_id), t._p(seq_id)->m_type.has_key());
+    EXPECT_EQ(t.has_key(val_id), t._p(val_id)->m_type.has_key());
+    EXPECT_EQ(t.has_key(docval_id), t._p(docval_id)->m_type.has_key());
+    EXPECT_EQ(stream.has_key(), stream.get()->m_type.has_key());
+    EXPECT_EQ(doc.has_key(), doc.get()->m_type.has_key());
+    EXPECT_EQ(map.has_key(), map.get()->m_type.has_key());
+    EXPECT_EQ(keyval.has_key(), keyval.get()->m_type.has_key());
+    EXPECT_EQ(seq.has_key(), seq.get()->m_type.has_key());
+    EXPECT_EQ(val.has_key(), val.get()->m_type.has_key());
+    EXPECT_EQ(docval.has_key(), docval.get()->m_type.has_key());
+    EXPECT_EQ(mstream.has_key(), mstream.get()->m_type.has_key());
+    EXPECT_EQ(mdoc.has_key(), mdoc.get()->m_type.has_key());
+    EXPECT_EQ(mmap.has_key(), mmap.get()->m_type.has_key());
+    EXPECT_EQ(mkeyval.has_key(), mkeyval.get()->m_type.has_key());
+    EXPECT_EQ(mseq.has_key(), mseq.get()->m_type.has_key());
+    EXPECT_EQ(mval.has_key(), mval.get()->m_type.has_key());
+    EXPECT_EQ(mdocval.has_key(), mdocval.get()->m_type.has_key());
+}
+
+TEST(NodeType, is_keyval)
+{
+    EXPECT_FALSE(NodeType(NOTYPE).is_keyval());
+    EXPECT_FALSE(NodeType(KEY).is_keyval());
+    EXPECT_FALSE(NodeType(VAL).is_keyval());
+    EXPECT_TRUE(NodeType(KEYVAL).is_keyval());
+    EXPECT_FALSE(NodeType(DOCVAL).is_keyval());
+    EXPECT_FALSE(NodeType(KEYMAP).is_keyval());
+    EXPECT_FALSE(NodeType(KEYSEQ).is_keyval());
+}
+
+TEST(Tree, is_keyval)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: bar}
+seq: [foo, bar]
+---
+a scalar
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t docval_id = t.last_child(stream_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef docval = t.ref(docval_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mdocval = t.ref(docval_id);
+    EXPECT_FALSE(t.is_keyval(stream_id));
+    EXPECT_FALSE(t.is_keyval(doc_id));
+    EXPECT_FALSE(t.is_keyval(map_id));
+    EXPECT_TRUE(t.is_keyval(keyval_id));
+    EXPECT_FALSE(t.is_keyval(seq_id));
+    EXPECT_FALSE(t.is_keyval(val_id));
+    EXPECT_FALSE(t.is_keyval(docval_id));
+    EXPECT_FALSE(stream.is_keyval());
+    EXPECT_FALSE(doc.is_keyval());
+    EXPECT_FALSE(map.is_keyval());
+    EXPECT_TRUE(keyval.is_keyval());
+    EXPECT_FALSE(seq.is_keyval());
+    EXPECT_FALSE(val.is_keyval());
+    EXPECT_FALSE(docval.is_keyval());
+    EXPECT_FALSE(mstream.is_keyval());
+    EXPECT_FALSE(mdoc.is_keyval());
+    EXPECT_FALSE(mmap.is_keyval());
+    EXPECT_TRUE(mkeyval.is_keyval());
+    EXPECT_FALSE(mseq.is_keyval());
+    EXPECT_FALSE(mval.is_keyval());
+    EXPECT_FALSE(mdocval.is_keyval());
+    EXPECT_EQ(t.is_keyval(stream_id), t._p(stream_id)->m_type.is_keyval());
+    EXPECT_EQ(t.is_keyval(doc_id), t._p(doc_id)->m_type.is_keyval());
+    EXPECT_EQ(t.is_keyval(map_id), t._p(map_id)->m_type.is_keyval());
+    EXPECT_EQ(t.is_keyval(keyval_id), t._p(keyval_id)->m_type.is_keyval());
+    EXPECT_EQ(t.is_keyval(seq_id), t._p(seq_id)->m_type.is_keyval());
+    EXPECT_EQ(t.is_keyval(val_id), t._p(val_id)->m_type.is_keyval());
+    EXPECT_EQ(t.is_keyval(docval_id), t._p(docval_id)->m_type.is_keyval());
+    EXPECT_EQ(stream.is_keyval(), stream.get()->m_type.is_keyval());
+    EXPECT_EQ(doc.is_keyval(), doc.get()->m_type.is_keyval());
+    EXPECT_EQ(map.is_keyval(), map.get()->m_type.is_keyval());
+    EXPECT_EQ(keyval.is_keyval(), keyval.get()->m_type.is_keyval());
+    EXPECT_EQ(seq.is_keyval(), seq.get()->m_type.is_keyval());
+    EXPECT_EQ(val.is_keyval(), val.get()->m_type.is_keyval());
+    EXPECT_EQ(docval.is_keyval(), docval.get()->m_type.is_keyval());
+    EXPECT_EQ(mstream.is_keyval(), mstream.get()->m_type.is_keyval());
+    EXPECT_EQ(mdoc.is_keyval(), mdoc.get()->m_type.is_keyval());
+    EXPECT_EQ(mmap.is_keyval(), mmap.get()->m_type.is_keyval());
+    EXPECT_EQ(mkeyval.is_keyval(), mkeyval.get()->m_type.is_keyval());
+    EXPECT_EQ(mseq.is_keyval(), mseq.get()->m_type.is_keyval());
+    EXPECT_EQ(mval.is_keyval(), mval.get()->m_type.is_keyval());
+    EXPECT_EQ(mdocval.is_keyval(), mdocval.get()->m_type.is_keyval());
+}
+
+TEST(NodeType, has_key_tag)
+{
+    EXPECT_FALSE(NodeType().has_key_tag());
+    EXPECT_FALSE(NodeType(KEYTAG).has_key_tag());
+    EXPECT_TRUE(NodeType(KEY|KEYTAG).has_key_tag());
+}
+
+TEST(Tree, has_key_tag)
+{
+    Tree t = parse_in_arena(R"(--- !docmaptag
+!maptag map: {!footag foo: bar, notag: none}
+!seqtag seq: [!footag foo, bar]
+---
+a scalar
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t keyvalnotag_id = t.last_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t valnotag_id = t.last_child(seq_id);
+    const size_t docval_id = t.last_child(stream_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef keyvalnotag = t.ref(keyvalnotag_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef valnotag = t.ref(val_id);
+    ConstNodeRef docval = t.ref(docval_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mkeyvalnotag = t.ref(keyvalnotag_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mvalnotag = t.ref(val_id);
+    NodeRef mdocval = t.ref(docval_id);
+    EXPECT_FALSE(t.has_key_tag(stream_id));
+    EXPECT_FALSE(t.has_key_tag(doc_id));
+    EXPECT_TRUE(t.has_key_tag(map_id));
+    EXPECT_TRUE(t.has_key_tag(keyval_id));
+    EXPECT_FALSE(t.has_key_tag(keyvalnotag_id));
+    EXPECT_TRUE(t.has_key_tag(seq_id));
+    EXPECT_FALSE(t.has_key_tag(val_id));
+    EXPECT_FALSE(t.has_key_tag(valnotag_id));
+    EXPECT_FALSE(t.has_key_tag(docval_id));
+    EXPECT_FALSE(stream.has_key_tag());
+    EXPECT_FALSE(doc.has_key_tag());
+    EXPECT_TRUE(map.has_key_tag());
+    EXPECT_TRUE(keyval.has_key_tag());
+    EXPECT_FALSE(keyvalnotag.has_key_tag());
+    EXPECT_TRUE(seq.has_key_tag());
+    EXPECT_FALSE(val.has_key_tag());
+    EXPECT_FALSE(valnotag.has_key_tag());
+    EXPECT_FALSE(docval.has_key_tag());
+    EXPECT_FALSE(mstream.has_key_tag());
+    EXPECT_FALSE(mdoc.has_key_tag());
+    EXPECT_TRUE(mmap.has_key_tag());
+    EXPECT_TRUE(mkeyval.has_key_tag());
+    EXPECT_FALSE(mkeyvalnotag.has_key_tag());
+    EXPECT_TRUE(mseq.has_key_tag());
+    EXPECT_FALSE(mval.has_key_tag());
+    EXPECT_FALSE(mvalnotag.has_key_tag());
+    EXPECT_FALSE(mdocval.has_key_tag());
+    EXPECT_EQ(t.has_key_tag(stream_id), t._p(stream_id)->m_type.has_key_tag());
+    EXPECT_EQ(t.has_key_tag(doc_id), t._p(doc_id)->m_type.has_key_tag());
+    EXPECT_EQ(t.has_key_tag(map_id), t._p(map_id)->m_type.has_key_tag());
+    EXPECT_EQ(t.has_key_tag(keyval_id), t._p(keyval_id)->m_type.has_key_tag());
+    EXPECT_EQ(t.has_key_tag(keyvalnotag_id), t._p(keyvalnotag_id)->m_type.has_key_tag());
+    EXPECT_EQ(t.has_key_tag(seq_id), t._p(seq_id)->m_type.has_key_tag());
+    EXPECT_EQ(t.has_key_tag(val_id), t._p(val_id)->m_type.has_key_tag());
+    EXPECT_EQ(t.has_key_tag(valnotag_id), t._p(valnotag_id)->m_type.has_key_tag());
+    EXPECT_EQ(t.has_key_tag(docval_id), t._p(docval_id)->m_type.has_key_tag());
+    EXPECT_EQ(stream.has_key_tag(), stream.get()->m_type.has_key_tag());
+    EXPECT_EQ(doc.has_key_tag(), doc.get()->m_type.has_key_tag());
+    EXPECT_EQ(map.has_key_tag(), map.get()->m_type.has_key_tag());
+    EXPECT_EQ(keyval.has_key_tag(), keyval.get()->m_type.has_key_tag());
+    EXPECT_EQ(keyvalnotag.has_key_tag(), keyvalnotag.get()->m_type.has_key_tag());
+    EXPECT_EQ(seq.has_key_tag(), seq.get()->m_type.has_key_tag());
+    EXPECT_EQ(val.has_key_tag(), val.get()->m_type.has_key_tag());
+    EXPECT_EQ(valnotag.has_key_tag(), valnotag.get()->m_type.has_key_tag());
+    EXPECT_EQ(docval.has_key_tag(), docval.get()->m_type.has_key_tag());
+    EXPECT_EQ(mstream.has_key_tag(), mstream.get()->m_type.has_key_tag());
+    EXPECT_EQ(mdoc.has_key_tag(), mdoc.get()->m_type.has_key_tag());
+    EXPECT_EQ(mmap.has_key_tag(), mmap.get()->m_type.has_key_tag());
+    EXPECT_EQ(mkeyval.has_key_tag(), mkeyval.get()->m_type.has_key_tag());
+    EXPECT_EQ(mkeyvalnotag.has_key_tag(), mkeyvalnotag.get()->m_type.has_key_tag());
+    EXPECT_EQ(mseq.has_key_tag(), mseq.get()->m_type.has_key_tag());
+    EXPECT_EQ(mval.has_key_tag(), mval.get()->m_type.has_key_tag());
+    EXPECT_EQ(mvalnotag.has_key_tag(), mvalnotag.get()->m_type.has_key_tag());
+    EXPECT_EQ(mdocval.has_key_tag(), mdocval.get()->m_type.has_key_tag());
+}
+
+TEST(NodeType, has_val_tag)
+{
+    EXPECT_FALSE(NodeType().has_val_tag());
+    EXPECT_FALSE(NodeType(VALTAG).has_val_tag());
+    EXPECT_TRUE(NodeType(VAL|VALTAG).has_val_tag());
+}
+
+TEST(Tree, has_val_tag)
+{
+    Tree t = parse_in_arena(R"(--- !docmaptag
+map: !maptag {foo: !bartag bar, notag: none}
+seq: !seqtag [!footag foo, bar]
+---
+a scalar
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t keyvalnotag_id = t.last_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t valnotag_id = t.last_child(seq_id);
+    const size_t docval_id = t.last_child(stream_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef keyvalnotag = t.ref(keyvalnotag_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef valnotag = t.ref(valnotag_id);
+    ConstNodeRef docval = t.ref(docval_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mkeyvalnotag = t.ref(keyvalnotag_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mvalnotag = t.ref(valnotag_id);
+    NodeRef mdocval = t.ref(docval_id);
+    EXPECT_FALSE(t.has_val_tag(stream_id));
+    EXPECT_TRUE(t.has_val_tag(doc_id));
+    EXPECT_TRUE(t.has_val_tag(map_id));
+    EXPECT_TRUE(t.has_val_tag(keyval_id));
+    EXPECT_FALSE(t.has_val_tag(keyvalnotag_id));
+    EXPECT_TRUE(t.has_val_tag(seq_id));
+    EXPECT_TRUE(t.has_val_tag(val_id));
+    EXPECT_FALSE(t.has_val_tag(valnotag_id));
+    EXPECT_FALSE(t.has_val_tag(docval_id));
+    EXPECT_FALSE(stream.has_val_tag());
+    EXPECT_TRUE(doc.has_val_tag());
+    EXPECT_TRUE(map.has_val_tag());
+    EXPECT_TRUE(keyval.has_val_tag());
+    EXPECT_FALSE(keyvalnotag.has_val_tag());
+    EXPECT_TRUE(seq.has_val_tag());
+    EXPECT_TRUE(val.has_val_tag());
+    EXPECT_FALSE(valnotag.has_val_tag());
+    EXPECT_FALSE(docval.has_val_tag());
+    EXPECT_FALSE(mstream.has_val_tag());
+    EXPECT_TRUE(mdoc.has_val_tag());
+    EXPECT_TRUE(mmap.has_val_tag());
+    EXPECT_TRUE(mkeyval.has_val_tag());
+    EXPECT_FALSE(mkeyvalnotag.has_val_tag());
+    EXPECT_TRUE(mseq.has_val_tag());
+    EXPECT_TRUE(mval.has_val_tag());
+    EXPECT_FALSE(mvalnotag.has_val_tag());
+    EXPECT_FALSE(mdocval.has_val_tag());
+    EXPECT_EQ(t.has_val_tag(stream_id), t._p(stream_id)->m_type.has_val_tag());
+    EXPECT_EQ(t.has_val_tag(doc_id), t._p(doc_id)->m_type.has_val_tag());
+    EXPECT_EQ(t.has_val_tag(map_id), t._p(map_id)->m_type.has_val_tag());
+    EXPECT_EQ(t.has_val_tag(keyval_id), t._p(keyval_id)->m_type.has_val_tag());
+    EXPECT_EQ(t.has_val_tag(keyvalnotag_id), t._p(keyvalnotag_id)->m_type.has_val_tag());
+    EXPECT_EQ(t.has_val_tag(seq_id), t._p(seq_id)->m_type.has_val_tag());
+    EXPECT_EQ(t.has_val_tag(val_id), t._p(val_id)->m_type.has_val_tag());
+    EXPECT_EQ(t.has_val_tag(valnotag_id), t._p(valnotag_id)->m_type.has_val_tag());
+    EXPECT_EQ(t.has_val_tag(docval_id), t._p(docval_id)->m_type.has_val_tag());
+    EXPECT_EQ(stream.has_val_tag(), stream.get()->m_type.has_val_tag());
+    EXPECT_EQ(doc.has_val_tag(), doc.get()->m_type.has_val_tag());
+    EXPECT_EQ(map.has_val_tag(), map.get()->m_type.has_val_tag());
+    EXPECT_EQ(keyval.has_val_tag(), keyval.get()->m_type.has_val_tag());
+    EXPECT_EQ(keyvalnotag.has_val_tag(), keyvalnotag.get()->m_type.has_val_tag());
+    EXPECT_EQ(seq.has_val_tag(), seq.get()->m_type.has_val_tag());
+    EXPECT_EQ(val.has_val_tag(), val.get()->m_type.has_val_tag());
+    EXPECT_EQ(valnotag.has_val_tag(), valnotag.get()->m_type.has_val_tag());
+    EXPECT_EQ(docval.has_val_tag(), docval.get()->m_type.has_val_tag());
+    EXPECT_EQ(mstream.has_val_tag(), mstream.get()->m_type.has_val_tag());
+    EXPECT_EQ(mdoc.has_val_tag(), mdoc.get()->m_type.has_val_tag());
+    EXPECT_EQ(mmap.has_val_tag(), mmap.get()->m_type.has_val_tag());
+    EXPECT_EQ(mkeyval.has_val_tag(), mkeyval.get()->m_type.has_val_tag());
+    EXPECT_EQ(mkeyvalnotag.has_val_tag(), mkeyvalnotag.get()->m_type.has_val_tag());
+    EXPECT_EQ(mseq.has_val_tag(), mseq.get()->m_type.has_val_tag());
+    EXPECT_EQ(mval.has_val_tag(), mval.get()->m_type.has_val_tag());
+    EXPECT_EQ(mvalnotag.has_val_tag(), mvalnotag.get()->m_type.has_val_tag());
+    EXPECT_EQ(mdocval.has_val_tag(), mdocval.get()->m_type.has_val_tag());
+}
+
+TEST(NodeType, has_key_anchor)
+{
+    EXPECT_FALSE(NodeType().has_key_anchor());
+    EXPECT_FALSE(NodeType(KEYANCH).has_key_anchor());
+    EXPECT_TRUE(NodeType(KEY|KEYANCH).has_key_anchor());
+}
+
+TEST(Tree, has_key_anchor)
+{
+    Tree t = parse_in_arena(R"(--- &docanchor
+&mapanchor map: {&keyvalanchor foo: bar, anchor: none}
+&seqanchor seq: [&valanchor foo, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t keyvalnoanchor_id = t.last_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t valnoanchor_id = t.last_child(seq_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef keyvalnoanchor = t.ref(keyvalnoanchor_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef valnoanchor = t.ref(valnoanchor_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mkeyvalnoanchor = t.ref(keyvalnoanchor_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mvalnoanchor = t.ref(valnoanchor_id);
+    EXPECT_FALSE(t.has_key_anchor(stream_id));
+    EXPECT_FALSE(t.has_key_anchor(doc_id));
+    EXPECT_TRUE(t.has_key_anchor(map_id));
+    EXPECT_TRUE(t.has_key_anchor(keyval_id));
+    EXPECT_FALSE(t.has_key_anchor(keyvalnoanchor_id));
+    EXPECT_TRUE(t.has_key_anchor(seq_id));
+    EXPECT_FALSE(t.has_key_anchor(val_id));
+    EXPECT_FALSE(t.has_key_anchor(valnoanchor_id));
+    EXPECT_FALSE(stream.has_key_anchor());
+    EXPECT_FALSE(doc.has_key_anchor());
+    EXPECT_TRUE(map.has_key_anchor());
+    EXPECT_TRUE(keyval.has_key_anchor());
+    EXPECT_FALSE(keyvalnoanchor.has_key_anchor());
+    EXPECT_TRUE(seq.has_key_anchor());
+    EXPECT_FALSE(val.has_key_anchor());
+    EXPECT_FALSE(valnoanchor.has_key_anchor());
+    EXPECT_FALSE(mstream.has_key_anchor());
+    EXPECT_FALSE(mdoc.has_key_anchor());
+    EXPECT_TRUE(mmap.has_key_anchor());
+    EXPECT_TRUE(mkeyval.has_key_anchor());
+    EXPECT_FALSE(mkeyvalnoanchor.has_key_anchor());
+    EXPECT_TRUE(mseq.has_key_anchor());
+    EXPECT_FALSE(mval.has_key_anchor());
+    EXPECT_FALSE(mvalnoanchor.has_key_anchor());
+    EXPECT_EQ(t.has_key_anchor(stream_id), t._p(stream_id)->m_type.has_key_anchor());
+    EXPECT_EQ(t.has_key_anchor(doc_id), t._p(doc_id)->m_type.has_key_anchor());
+    EXPECT_EQ(t.has_key_anchor(map_id), t._p(map_id)->m_type.has_key_anchor());
+    EXPECT_EQ(t.has_key_anchor(keyval_id), t._p(keyval_id)->m_type.has_key_anchor());
+    EXPECT_EQ(t.has_key_anchor(keyvalnoanchor_id), t._p(keyvalnoanchor_id)->m_type.has_key_anchor());
+    EXPECT_EQ(t.has_key_anchor(seq_id), t._p(seq_id)->m_type.has_key_anchor());
+    EXPECT_EQ(t.has_key_anchor(val_id), t._p(val_id)->m_type.has_key_anchor());
+    EXPECT_EQ(t.has_key_anchor(valnoanchor_id), t._p(valnoanchor_id)->m_type.has_key_anchor());
+    EXPECT_EQ(stream.has_key_anchor(), stream.get()->m_type.has_key_anchor());
+    EXPECT_EQ(doc.has_key_anchor(), doc.get()->m_type.has_key_anchor());
+    EXPECT_EQ(map.has_key_anchor(), map.get()->m_type.has_key_anchor());
+    EXPECT_EQ(keyval.has_key_anchor(), keyval.get()->m_type.has_key_anchor());
+    EXPECT_EQ(keyvalnoanchor.has_key_anchor(), keyvalnoanchor.get()->m_type.has_key_anchor());
+    EXPECT_EQ(seq.has_key_anchor(), seq.get()->m_type.has_key_anchor());
+    EXPECT_EQ(val.has_key_anchor(), val.get()->m_type.has_key_anchor());
+    EXPECT_EQ(valnoanchor.has_key_anchor(), valnoanchor.get()->m_type.has_key_anchor());
+    EXPECT_EQ(mstream.has_key_anchor(), mstream.get()->m_type.has_key_anchor());
+    EXPECT_EQ(mdoc.has_key_anchor(), mdoc.get()->m_type.has_key_anchor());
+    EXPECT_EQ(mmap.has_key_anchor(), mmap.get()->m_type.has_key_anchor());
+    EXPECT_EQ(mkeyval.has_key_anchor(), mkeyval.get()->m_type.has_key_anchor());
+    EXPECT_EQ(mkeyvalnoanchor.has_key_anchor(), mkeyvalnoanchor.get()->m_type.has_key_anchor());
+    EXPECT_EQ(mseq.has_key_anchor(), mseq.get()->m_type.has_key_anchor());
+    EXPECT_EQ(mval.has_key_anchor(), mval.get()->m_type.has_key_anchor());
+    EXPECT_EQ(mvalnoanchor.has_key_anchor(), mvalnoanchor.get()->m_type.has_key_anchor());
+}
+
+TEST(NodeType, is_key_anchor)
+{
+    EXPECT_FALSE(NodeType().is_key_anchor());
+    EXPECT_FALSE(NodeType(KEYANCH).is_key_anchor());
+    EXPECT_TRUE(NodeType(KEY|KEYANCH).is_key_anchor());
+}
+
+TEST(Tree, is_key_anchor)
+{
+    Tree t = parse_in_arena(R"(--- &docanchor
+&mapanchor map: {&keyvalanchor foo: bar, anchor: none}
+&seqanchor seq: [&valanchor foo, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t keyvalnoanchor_id = t.last_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t valnoanchor_id = t.last_child(seq_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef keyvalnoanchor = t.ref(keyvalnoanchor_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef valnoanchor = t.ref(valnoanchor_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mkeyvalnoanchor = t.ref(keyvalnoanchor_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mvalnoanchor = t.ref(valnoanchor_id);
+    EXPECT_FALSE(t.is_key_anchor(stream_id));
+    EXPECT_FALSE(t.is_key_anchor(doc_id));
+    EXPECT_TRUE(t.is_key_anchor(map_id));
+    EXPECT_TRUE(t.is_key_anchor(keyval_id));
+    EXPECT_FALSE(t.is_key_anchor(keyvalnoanchor_id));
+    EXPECT_TRUE(t.is_key_anchor(seq_id));
+    EXPECT_FALSE(t.is_key_anchor(val_id));
+    EXPECT_FALSE(t.is_key_anchor(valnoanchor_id));
+    EXPECT_FALSE(stream.is_key_anchor());
+    EXPECT_FALSE(doc.is_key_anchor());
+    EXPECT_TRUE(map.is_key_anchor());
+    EXPECT_TRUE(keyval.is_key_anchor());
+    EXPECT_FALSE(keyvalnoanchor.is_key_anchor());
+    EXPECT_TRUE(seq.is_key_anchor());
+    EXPECT_FALSE(val.is_key_anchor());
+    EXPECT_FALSE(valnoanchor.is_key_anchor());
+    EXPECT_FALSE(mstream.is_key_anchor());
+    EXPECT_FALSE(mdoc.is_key_anchor());
+    EXPECT_TRUE(mmap.is_key_anchor());
+    EXPECT_TRUE(mkeyval.is_key_anchor());
+    EXPECT_FALSE(mkeyvalnoanchor.is_key_anchor());
+    EXPECT_TRUE(mseq.is_key_anchor());
+    EXPECT_FALSE(mval.is_key_anchor());
+    EXPECT_FALSE(mvalnoanchor.is_key_anchor());
+    EXPECT_EQ(t.is_key_anchor(stream_id), t._p(stream_id)->m_type.is_key_anchor());
+    EXPECT_EQ(t.is_key_anchor(doc_id), t._p(doc_id)->m_type.is_key_anchor());
+    EXPECT_EQ(t.is_key_anchor(map_id), t._p(map_id)->m_type.is_key_anchor());
+    EXPECT_EQ(t.is_key_anchor(keyval_id), t._p(keyval_id)->m_type.is_key_anchor());
+    EXPECT_EQ(t.is_key_anchor(keyvalnoanchor_id), t._p(keyvalnoanchor_id)->m_type.is_key_anchor());
+    EXPECT_EQ(t.is_key_anchor(seq_id), t._p(seq_id)->m_type.is_key_anchor());
+    EXPECT_EQ(t.is_key_anchor(val_id), t._p(val_id)->m_type.is_key_anchor());
+    EXPECT_EQ(t.is_key_anchor(valnoanchor_id), t._p(valnoanchor_id)->m_type.is_key_anchor());
+    EXPECT_EQ(stream.is_key_anchor(), stream.get()->m_type.is_key_anchor());
+    EXPECT_EQ(doc.is_key_anchor(), doc.get()->m_type.is_key_anchor());
+    EXPECT_EQ(map.is_key_anchor(), map.get()->m_type.is_key_anchor());
+    EXPECT_EQ(keyval.is_key_anchor(), keyval.get()->m_type.is_key_anchor());
+    EXPECT_EQ(keyvalnoanchor.is_key_anchor(), keyvalnoanchor.get()->m_type.is_key_anchor());
+    EXPECT_EQ(seq.is_key_anchor(), seq.get()->m_type.is_key_anchor());
+    EXPECT_EQ(val.is_key_anchor(), val.get()->m_type.is_key_anchor());
+    EXPECT_EQ(valnoanchor.is_key_anchor(), valnoanchor.get()->m_type.is_key_anchor());
+    EXPECT_EQ(mstream.is_key_anchor(), mstream.get()->m_type.is_key_anchor());
+    EXPECT_EQ(mdoc.is_key_anchor(), mdoc.get()->m_type.is_key_anchor());
+    EXPECT_EQ(mmap.is_key_anchor(), mmap.get()->m_type.is_key_anchor());
+    EXPECT_EQ(mkeyval.is_key_anchor(), mkeyval.get()->m_type.is_key_anchor());
+    EXPECT_EQ(mkeyvalnoanchor.is_key_anchor(), mkeyvalnoanchor.get()->m_type.is_key_anchor());
+    EXPECT_EQ(mseq.is_key_anchor(), mseq.get()->m_type.is_key_anchor());
+    EXPECT_EQ(mval.is_key_anchor(), mval.get()->m_type.is_key_anchor());
+    EXPECT_EQ(mvalnoanchor.is_key_anchor(), mvalnoanchor.get()->m_type.is_key_anchor());
+}
+
+TEST(NodeType, has_val_anchor)
+{
+    EXPECT_FALSE(NodeType().has_val_anchor());
+    EXPECT_FALSE(NodeType(VALANCH).has_val_anchor());
+    EXPECT_TRUE(NodeType(VAL|VALANCH).has_val_anchor());
+}
+
+TEST(Tree, has_val_anchor)
+{
+    Tree t = parse_in_arena(R"(--- &docanchor
+map: &mapanchor {foo: &keyvalanchor bar, anchor: none}
+seq: &seqanchor [&valanchor foo, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t keyvalnoanchor_id = t.last_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t valnoanchor_id = t.last_child(seq_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef keyvalnoanchor = t.ref(keyvalnoanchor_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef valnoanchor = t.ref(valnoanchor_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mkeyvalnoanchor = t.ref(keyvalnoanchor_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mvalnoanchor = t.ref(valnoanchor_id);
+    EXPECT_FALSE(t.has_val_anchor(stream_id));
+    EXPECT_FALSE(t.has_val_anchor(doc_id));
+    EXPECT_TRUE(t.has_val_anchor(map_id));
+    EXPECT_TRUE(t.has_val_anchor(keyval_id));
+    EXPECT_FALSE(t.has_val_anchor(keyvalnoanchor_id));
+    EXPECT_TRUE(t.has_val_anchor(seq_id));
+    EXPECT_TRUE(t.has_val_anchor(val_id));
+    EXPECT_FALSE(t.has_val_anchor(valnoanchor_id));
+    EXPECT_FALSE(stream.has_val_anchor());
+    EXPECT_FALSE(doc.has_val_anchor());
+    EXPECT_TRUE(map.has_val_anchor());
+    EXPECT_TRUE(keyval.has_val_anchor());
+    EXPECT_FALSE(keyvalnoanchor.has_val_anchor());
+    EXPECT_TRUE(seq.has_val_anchor());
+    EXPECT_TRUE(val.has_val_anchor());
+    EXPECT_FALSE(valnoanchor.has_val_anchor());
+    EXPECT_FALSE(mstream.has_val_anchor());
+    EXPECT_FALSE(mdoc.has_val_anchor());
+    EXPECT_TRUE(mmap.has_val_anchor());
+    EXPECT_TRUE(mkeyval.has_val_anchor());
+    EXPECT_FALSE(mkeyvalnoanchor.has_val_anchor());
+    EXPECT_TRUE(mseq.has_val_anchor());
+    EXPECT_TRUE(mval.has_val_anchor());
+    EXPECT_FALSE(mvalnoanchor.has_val_anchor());
+    EXPECT_EQ(t.has_val_anchor(stream_id), t._p(stream_id)->m_type.has_val_anchor());
+    EXPECT_EQ(t.has_val_anchor(doc_id), t._p(doc_id)->m_type.has_val_anchor());
+    EXPECT_EQ(t.has_val_anchor(map_id), t._p(map_id)->m_type.has_val_anchor());
+    EXPECT_EQ(t.has_val_anchor(keyval_id), t._p(keyval_id)->m_type.has_val_anchor());
+    EXPECT_EQ(t.has_val_anchor(keyvalnoanchor_id), t._p(keyvalnoanchor_id)->m_type.has_val_anchor());
+    EXPECT_EQ(t.has_val_anchor(seq_id), t._p(seq_id)->m_type.has_val_anchor());
+    EXPECT_EQ(t.has_val_anchor(val_id), t._p(val_id)->m_type.has_val_anchor());
+    EXPECT_EQ(t.has_val_anchor(valnoanchor_id), t._p(valnoanchor_id)->m_type.has_val_anchor());
+    EXPECT_EQ(stream.has_val_anchor(), stream.get()->m_type.has_val_anchor());
+    EXPECT_EQ(doc.has_val_anchor(), doc.get()->m_type.has_val_anchor());
+    EXPECT_EQ(map.has_val_anchor(), map.get()->m_type.has_val_anchor());
+    EXPECT_EQ(keyval.has_val_anchor(), keyval.get()->m_type.has_val_anchor());
+    EXPECT_EQ(keyvalnoanchor.has_val_anchor(), keyvalnoanchor.get()->m_type.has_val_anchor());
+    EXPECT_EQ(seq.has_val_anchor(), seq.get()->m_type.has_val_anchor());
+    EXPECT_EQ(val.has_val_anchor(), val.get()->m_type.has_val_anchor());
+    EXPECT_EQ(valnoanchor.has_val_anchor(), valnoanchor.get()->m_type.has_val_anchor());
+    EXPECT_EQ(mstream.has_val_anchor(), mstream.get()->m_type.has_val_anchor());
+    EXPECT_EQ(mdoc.has_val_anchor(), mdoc.get()->m_type.has_val_anchor());
+    EXPECT_EQ(mmap.has_val_anchor(), mmap.get()->m_type.has_val_anchor());
+    EXPECT_EQ(mkeyval.has_val_anchor(), mkeyval.get()->m_type.has_val_anchor());
+    EXPECT_EQ(mkeyvalnoanchor.has_val_anchor(), mkeyvalnoanchor.get()->m_type.has_val_anchor());
+    EXPECT_EQ(mseq.has_val_anchor(), mseq.get()->m_type.has_val_anchor());
+    EXPECT_EQ(mval.has_val_anchor(), mval.get()->m_type.has_val_anchor());
+    EXPECT_EQ(mvalnoanchor.has_val_anchor(), mvalnoanchor.get()->m_type.has_val_anchor());
+}
+
+TEST(NodeType, is_val_anchor)
+{
+    EXPECT_FALSE(NodeType().is_val_anchor());
+    EXPECT_FALSE(NodeType(VALANCH).is_val_anchor());
+    EXPECT_TRUE(NodeType(VAL|VALANCH).is_val_anchor());
+}
+
+TEST(Tree, is_val_anchor)
+{
+    Tree t = parse_in_arena(R"(--- &docanchor
+map: &mapanchor {foo: &keyvalanchor bar, anchor: none}
+seq: &seqanchor [&valanchor foo, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t keyvalnoanchor_id = t.last_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t valnoanchor_id = t.last_child(seq_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef keyvalnoanchor = t.ref(keyvalnoanchor_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef valnoanchor = t.ref(valnoanchor_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mkeyvalnoanchor = t.ref(keyvalnoanchor_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mvalnoanchor = t.ref(valnoanchor_id);
+    EXPECT_FALSE(t.is_val_anchor(stream_id));
+    EXPECT_FALSE(t.is_val_anchor(doc_id));
+    EXPECT_TRUE(t.is_val_anchor(map_id));
+    EXPECT_TRUE(t.is_val_anchor(keyval_id));
+    EXPECT_FALSE(t.is_val_anchor(keyvalnoanchor_id));
+    EXPECT_TRUE(t.is_val_anchor(seq_id));
+    EXPECT_TRUE(t.is_val_anchor(val_id));
+    EXPECT_FALSE(t.is_val_anchor(valnoanchor_id));
+    EXPECT_FALSE(stream.is_val_anchor());
+    EXPECT_FALSE(doc.is_val_anchor());
+    EXPECT_TRUE(map.is_val_anchor());
+    EXPECT_TRUE(keyval.is_val_anchor());
+    EXPECT_FALSE(keyvalnoanchor.is_val_anchor());
+    EXPECT_TRUE(seq.is_val_anchor());
+    EXPECT_TRUE(val.is_val_anchor());
+    EXPECT_FALSE(valnoanchor.is_val_anchor());
+    EXPECT_FALSE(mstream.is_val_anchor());
+    EXPECT_FALSE(mdoc.is_val_anchor());
+    EXPECT_TRUE(mmap.is_val_anchor());
+    EXPECT_TRUE(mkeyval.is_val_anchor());
+    EXPECT_FALSE(mkeyvalnoanchor.is_val_anchor());
+    EXPECT_TRUE(mseq.is_val_anchor());
+    EXPECT_TRUE(mval.is_val_anchor());
+    EXPECT_FALSE(mvalnoanchor.is_val_anchor());
+    EXPECT_EQ(t.is_val_anchor(stream_id), t._p(stream_id)->m_type.is_val_anchor());
+    EXPECT_EQ(t.is_val_anchor(doc_id), t._p(doc_id)->m_type.is_val_anchor());
+    EXPECT_EQ(t.is_val_anchor(map_id), t._p(map_id)->m_type.is_val_anchor());
+    EXPECT_EQ(t.is_val_anchor(keyval_id), t._p(keyval_id)->m_type.is_val_anchor());
+    EXPECT_EQ(t.is_val_anchor(keyvalnoanchor_id), t._p(keyvalnoanchor_id)->m_type.is_val_anchor());
+    EXPECT_EQ(t.is_val_anchor(seq_id), t._p(seq_id)->m_type.is_val_anchor());
+    EXPECT_EQ(t.is_val_anchor(val_id), t._p(val_id)->m_type.is_val_anchor());
+    EXPECT_EQ(t.is_val_anchor(valnoanchor_id), t._p(valnoanchor_id)->m_type.is_val_anchor());
+    EXPECT_EQ(stream.is_val_anchor(), stream.get()->m_type.is_val_anchor());
+    EXPECT_EQ(doc.is_val_anchor(), doc.get()->m_type.is_val_anchor());
+    EXPECT_EQ(map.is_val_anchor(), map.get()->m_type.is_val_anchor());
+    EXPECT_EQ(keyval.is_val_anchor(), keyval.get()->m_type.is_val_anchor());
+    EXPECT_EQ(keyvalnoanchor.is_val_anchor(), keyvalnoanchor.get()->m_type.is_val_anchor());
+    EXPECT_EQ(seq.is_val_anchor(), seq.get()->m_type.is_val_anchor());
+    EXPECT_EQ(val.is_val_anchor(), val.get()->m_type.is_val_anchor());
+    EXPECT_EQ(valnoanchor.is_val_anchor(), valnoanchor.get()->m_type.is_val_anchor());
+    EXPECT_EQ(mstream.is_val_anchor(), mstream.get()->m_type.is_val_anchor());
+    EXPECT_EQ(mdoc.is_val_anchor(), mdoc.get()->m_type.is_val_anchor());
+    EXPECT_EQ(mmap.is_val_anchor(), mmap.get()->m_type.is_val_anchor());
+    EXPECT_EQ(mkeyval.is_val_anchor(), mkeyval.get()->m_type.is_val_anchor());
+    EXPECT_EQ(mkeyvalnoanchor.is_val_anchor(), mkeyvalnoanchor.get()->m_type.is_val_anchor());
+    EXPECT_EQ(mseq.is_val_anchor(), mseq.get()->m_type.is_val_anchor());
+    EXPECT_EQ(mval.is_val_anchor(), mval.get()->m_type.is_val_anchor());
+    EXPECT_EQ(mvalnoanchor.is_val_anchor(), mvalnoanchor.get()->m_type.is_val_anchor());
+}
+
+TEST(NodeType, has_anchor)
+{
+    EXPECT_FALSE(NodeType().has_anchor());
+    EXPECT_TRUE(NodeType(VALANCH).has_anchor());
+    EXPECT_TRUE(NodeType(KEYANCH).has_anchor());
+    EXPECT_TRUE(NodeType(KEYANCH|VALANCH).has_anchor());
+    EXPECT_TRUE(NodeType(KEY|VALANCH).has_anchor());
+    EXPECT_TRUE(NodeType(VAL|KEYANCH).has_anchor());
+    EXPECT_TRUE(NodeType(KEY|KEYANCH).has_anchor());
+    EXPECT_TRUE(NodeType(VAL|VALANCH).has_anchor());
+}
+
+TEST(Tree, has_anchor)
+{
+    Tree t = parse_in_arena(R"(--- &docanchor
+map: &mapanchor {foo: &keyvalanchor bar, anchor: none}
+&seqanchor seq: [&valanchor foo, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t keyvalnoanchor_id = t.last_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t valnoanchor_id = t.last_child(seq_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef keyvalnoanchor = t.ref(keyvalnoanchor_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef valnoanchor = t.ref(valnoanchor_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mkeyvalnoanchor = t.ref(keyvalnoanchor_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mvalnoanchor = t.ref(valnoanchor_id);
+    EXPECT_FALSE(t.has_anchor(stream_id));
+    EXPECT_FALSE(t.has_anchor(doc_id));
+    EXPECT_TRUE(t.has_anchor(map_id));
+    EXPECT_TRUE(t.has_anchor(keyval_id));
+    EXPECT_FALSE(t.has_anchor(keyvalnoanchor_id));
+    EXPECT_TRUE(t.has_anchor(seq_id));
+    EXPECT_TRUE(t.has_anchor(val_id));
+    EXPECT_FALSE(t.has_anchor(valnoanchor_id));
+    EXPECT_FALSE(stream.has_anchor());
+    EXPECT_FALSE(doc.has_anchor());
+    EXPECT_TRUE(map.has_anchor());
+    EXPECT_TRUE(keyval.has_anchor());
+    EXPECT_FALSE(keyvalnoanchor.has_anchor());
+    EXPECT_TRUE(seq.has_anchor());
+    EXPECT_TRUE(val.has_anchor());
+    EXPECT_FALSE(valnoanchor.has_anchor());
+    EXPECT_FALSE(mstream.has_anchor());
+    EXPECT_FALSE(mdoc.has_anchor());
+    EXPECT_TRUE(mmap.has_anchor());
+    EXPECT_TRUE(mkeyval.has_anchor());
+    EXPECT_FALSE(mkeyvalnoanchor.has_anchor());
+    EXPECT_TRUE(mseq.has_anchor());
+    EXPECT_TRUE(mval.has_anchor());
+    EXPECT_FALSE(mvalnoanchor.has_anchor());
+    EXPECT_EQ(t.has_anchor(stream_id), t._p(stream_id)->m_type.has_anchor());
+    EXPECT_EQ(t.has_anchor(doc_id), t._p(doc_id)->m_type.has_anchor());
+    EXPECT_EQ(t.has_anchor(map_id), t._p(map_id)->m_type.has_anchor());
+    EXPECT_EQ(t.has_anchor(keyval_id), t._p(keyval_id)->m_type.has_anchor());
+    EXPECT_EQ(t.has_anchor(keyvalnoanchor_id), t._p(keyvalnoanchor_id)->m_type.has_anchor());
+    EXPECT_EQ(t.has_anchor(seq_id), t._p(seq_id)->m_type.has_anchor());
+    EXPECT_EQ(t.has_anchor(val_id), t._p(val_id)->m_type.has_anchor());
+    EXPECT_EQ(t.has_anchor(valnoanchor_id), t._p(valnoanchor_id)->m_type.has_anchor());
+    EXPECT_EQ(stream.has_anchor(), stream.get()->m_type.has_anchor());
+    EXPECT_EQ(doc.has_anchor(), doc.get()->m_type.has_anchor());
+    EXPECT_EQ(map.has_anchor(), map.get()->m_type.has_anchor());
+    EXPECT_EQ(keyval.has_anchor(), keyval.get()->m_type.has_anchor());
+    EXPECT_EQ(keyvalnoanchor.has_anchor(), keyvalnoanchor.get()->m_type.has_anchor());
+    EXPECT_EQ(seq.has_anchor(), seq.get()->m_type.has_anchor());
+    EXPECT_EQ(val.has_anchor(), val.get()->m_type.has_anchor());
+    EXPECT_EQ(valnoanchor.has_anchor(), valnoanchor.get()->m_type.has_anchor());
+    EXPECT_EQ(mstream.has_anchor(), mstream.get()->m_type.has_anchor());
+    EXPECT_EQ(mdoc.has_anchor(), mdoc.get()->m_type.has_anchor());
+    EXPECT_EQ(mmap.has_anchor(), mmap.get()->m_type.has_anchor());
+    EXPECT_EQ(mkeyval.has_anchor(), mkeyval.get()->m_type.has_anchor());
+    EXPECT_EQ(mkeyvalnoanchor.has_anchor(), mkeyvalnoanchor.get()->m_type.has_anchor());
+    EXPECT_EQ(mseq.has_anchor(), mseq.get()->m_type.has_anchor());
+    EXPECT_EQ(mval.has_anchor(), mval.get()->m_type.has_anchor());
+    EXPECT_EQ(mvalnoanchor.has_anchor(), mvalnoanchor.get()->m_type.has_anchor());
+}
+
+TEST(NodeType, is_anchor)
+{
+    EXPECT_FALSE(NodeType().is_anchor());
+    EXPECT_TRUE(NodeType(VALANCH).is_anchor());
+    EXPECT_TRUE(NodeType(KEYANCH).is_anchor());
+    EXPECT_TRUE(NodeType(KEYANCH|VALANCH).is_anchor());
+    EXPECT_TRUE(NodeType(KEY|VALANCH).is_anchor());
+    EXPECT_TRUE(NodeType(VAL|KEYANCH).is_anchor());
+    EXPECT_TRUE(NodeType(KEY|KEYANCH).is_anchor());
+    EXPECT_TRUE(NodeType(VAL|VALANCH).is_anchor());
+}
+
+TEST(Tree, is_anchor)
+{
+    Tree t = parse_in_arena(R"(--- &docanchor
+map: &mapanchor {foo: &keyvalanchor bar, anchor: none}
+&seqanchor seq: [&valanchor foo, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t keyvalnoanchor_id = t.last_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    const size_t valnoanchor_id = t.last_child(seq_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef keyvalnoanchor = t.ref(keyvalnoanchor_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    ConstNodeRef valnoanchor = t.ref(valnoanchor_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mkeyvalnoanchor = t.ref(keyvalnoanchor_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    NodeRef mvalnoanchor = t.ref(valnoanchor_id);
+    EXPECT_FALSE(t.is_anchor(stream_id));
+    EXPECT_FALSE(t.is_anchor(doc_id));
+    EXPECT_TRUE(t.is_anchor(map_id));
+    EXPECT_TRUE(t.is_anchor(keyval_id));
+    EXPECT_FALSE(t.is_anchor(keyvalnoanchor_id));
+    EXPECT_TRUE(t.is_anchor(seq_id));
+    EXPECT_TRUE(t.is_anchor(val_id));
+    EXPECT_FALSE(t.is_anchor(valnoanchor_id));
+    EXPECT_FALSE(stream.is_anchor());
+    EXPECT_FALSE(doc.is_anchor());
+    EXPECT_TRUE(map.is_anchor());
+    EXPECT_TRUE(keyval.is_anchor());
+    EXPECT_FALSE(keyvalnoanchor.is_anchor());
+    EXPECT_TRUE(seq.is_anchor());
+    EXPECT_TRUE(val.is_anchor());
+    EXPECT_FALSE(valnoanchor.is_anchor());
+    EXPECT_FALSE(mstream.is_anchor());
+    EXPECT_FALSE(mdoc.is_anchor());
+    EXPECT_TRUE(mmap.is_anchor());
+    EXPECT_TRUE(mkeyval.is_anchor());
+    EXPECT_FALSE(mkeyvalnoanchor.is_anchor());
+    EXPECT_TRUE(mseq.is_anchor());
+    EXPECT_TRUE(mval.is_anchor());
+    EXPECT_FALSE(mvalnoanchor.is_anchor());
+    EXPECT_EQ(t.is_anchor(stream_id), t._p(stream_id)->m_type.is_anchor());
+    EXPECT_EQ(t.is_anchor(doc_id), t._p(doc_id)->m_type.is_anchor());
+    EXPECT_EQ(t.is_anchor(map_id), t._p(map_id)->m_type.is_anchor());
+    EXPECT_EQ(t.is_anchor(keyval_id), t._p(keyval_id)->m_type.is_anchor());
+    EXPECT_EQ(t.is_anchor(keyvalnoanchor_id), t._p(keyvalnoanchor_id)->m_type.is_anchor());
+    EXPECT_EQ(t.is_anchor(seq_id), t._p(seq_id)->m_type.is_anchor());
+    EXPECT_EQ(t.is_anchor(val_id), t._p(val_id)->m_type.is_anchor());
+    EXPECT_EQ(t.is_anchor(valnoanchor_id), t._p(valnoanchor_id)->m_type.is_anchor());
+    EXPECT_EQ(stream.is_anchor(), stream.get()->m_type.is_anchor());
+    EXPECT_EQ(doc.is_anchor(), doc.get()->m_type.is_anchor());
+    EXPECT_EQ(map.is_anchor(), map.get()->m_type.is_anchor());
+    EXPECT_EQ(keyval.is_anchor(), keyval.get()->m_type.is_anchor());
+    EXPECT_EQ(keyvalnoanchor.is_anchor(), keyvalnoanchor.get()->m_type.is_anchor());
+    EXPECT_EQ(seq.is_anchor(), seq.get()->m_type.is_anchor());
+    EXPECT_EQ(val.is_anchor(), val.get()->m_type.is_anchor());
+    EXPECT_EQ(valnoanchor.is_anchor(), valnoanchor.get()->m_type.is_anchor());
+    EXPECT_EQ(mstream.is_anchor(), mstream.get()->m_type.is_anchor());
+    EXPECT_EQ(mdoc.is_anchor(), mdoc.get()->m_type.is_anchor());
+    EXPECT_EQ(mmap.is_anchor(), mmap.get()->m_type.is_anchor());
+    EXPECT_EQ(mkeyval.is_anchor(), mkeyval.get()->m_type.is_anchor());
+    EXPECT_EQ(mkeyvalnoanchor.is_anchor(), mkeyvalnoanchor.get()->m_type.is_anchor());
+    EXPECT_EQ(mseq.is_anchor(), mseq.get()->m_type.is_anchor());
+    EXPECT_EQ(mval.is_anchor(), mval.get()->m_type.is_anchor());
+    EXPECT_EQ(mvalnoanchor.is_anchor(), mvalnoanchor.get()->m_type.is_anchor());
+}
+
+TEST(NodeType, is_key_ref)
+{
+    EXPECT_FALSE(NodeType().is_key_ref());
+    EXPECT_TRUE(NodeType(KEYREF).is_key_ref());
+    EXPECT_TRUE(NodeType(KEY|KEYREF).is_key_ref());
+}
+
+TEST(Tree, is_key_ref)
+{
+    Tree t = parse_in_arena(R"(---
+*mapref: {foo: bar, notag: none}
+*seqref: [foo, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    EXPECT_FALSE(t.is_key_ref(stream_id));
+    EXPECT_FALSE(t.is_key_ref(doc_id));
+    EXPECT_TRUE(t.is_key_ref(map_id));
+    EXPECT_FALSE(t.is_key_ref(keyval_id));
+    EXPECT_TRUE(t.is_key_ref(seq_id));
+    EXPECT_FALSE(t.is_key_ref(val_id));
+    EXPECT_FALSE(stream.is_key_ref());
+    EXPECT_FALSE(doc.is_key_ref());
+    EXPECT_TRUE(map.is_key_ref());
+    EXPECT_FALSE(keyval.is_key_ref());
+    EXPECT_TRUE(seq.is_key_ref());
+    EXPECT_FALSE(val.is_key_ref());
+    EXPECT_FALSE(mstream.is_key_ref());
+    EXPECT_FALSE(mdoc.is_key_ref());
+    EXPECT_TRUE(mmap.is_key_ref());
+    EXPECT_FALSE(mkeyval.is_key_ref());
+    EXPECT_TRUE(mseq.is_key_ref());
+    EXPECT_FALSE(mval.is_key_ref());
+    EXPECT_EQ(t.is_key_ref(stream_id), t._p(stream_id)->m_type.is_key_ref());
+    EXPECT_EQ(t.is_key_ref(doc_id), t._p(doc_id)->m_type.is_key_ref());
+    EXPECT_EQ(t.is_key_ref(map_id), t._p(map_id)->m_type.is_key_ref());
+    EXPECT_EQ(t.is_key_ref(keyval_id), t._p(keyval_id)->m_type.is_key_ref());
+    EXPECT_EQ(t.is_key_ref(seq_id), t._p(seq_id)->m_type.is_key_ref());
+    EXPECT_EQ(t.is_key_ref(val_id), t._p(val_id)->m_type.is_key_ref());
+    EXPECT_EQ(stream.is_key_ref(), stream.get()->m_type.is_key_ref());
+    EXPECT_EQ(doc.is_key_ref(), doc.get()->m_type.is_key_ref());
+    EXPECT_EQ(map.is_key_ref(), map.get()->m_type.is_key_ref());
+    EXPECT_EQ(keyval.is_key_ref(), keyval.get()->m_type.is_key_ref());
+    EXPECT_EQ(seq.is_key_ref(), seq.get()->m_type.is_key_ref());
+    EXPECT_EQ(val.is_key_ref(), val.get()->m_type.is_key_ref());
+    EXPECT_EQ(mstream.is_key_ref(), mstream.get()->m_type.is_key_ref());
+    EXPECT_EQ(mdoc.is_key_ref(), mdoc.get()->m_type.is_key_ref());
+    EXPECT_EQ(mmap.is_key_ref(), mmap.get()->m_type.is_key_ref());
+    EXPECT_EQ(mkeyval.is_key_ref(), mkeyval.get()->m_type.is_key_ref());
+    EXPECT_EQ(mseq.is_key_ref(), mseq.get()->m_type.is_key_ref());
+    EXPECT_EQ(mval.is_key_ref(), mval.get()->m_type.is_key_ref());
+}
+
+TEST(NodeType, is_val_ref)
+{
+    EXPECT_FALSE(NodeType().is_val_ref());
+    EXPECT_TRUE(NodeType(VALREF).is_val_ref());
+    EXPECT_TRUE(NodeType(VAL|VALREF).is_val_ref());
+}
+
+TEST(Tree, is_val_ref)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: *keyvalref, notag: none}
+seq: [*valref, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    EXPECT_FALSE(t.is_val_ref(stream_id));
+    EXPECT_FALSE(t.is_val_ref(doc_id));
+    EXPECT_FALSE(t.is_val_ref(map_id));
+    EXPECT_TRUE(t.is_val_ref(keyval_id));
+    EXPECT_FALSE(t.is_val_ref(seq_id));
+    EXPECT_TRUE(t.is_val_ref(val_id));
+    EXPECT_FALSE(stream.is_val_ref());
+    EXPECT_FALSE(doc.is_val_ref());
+    EXPECT_FALSE(map.is_val_ref());
+    EXPECT_TRUE(keyval.is_val_ref());
+    EXPECT_FALSE(seq.is_val_ref());
+    EXPECT_TRUE(val.is_val_ref());
+    EXPECT_FALSE(mstream.is_val_ref());
+    EXPECT_FALSE(mdoc.is_val_ref());
+    EXPECT_FALSE(mmap.is_val_ref());
+    EXPECT_TRUE(mkeyval.is_val_ref());
+    EXPECT_FALSE(mseq.is_val_ref());
+    EXPECT_TRUE(mval.is_val_ref());
+    EXPECT_EQ(t.is_val_ref(stream_id), t._p(stream_id)->m_type.is_val_ref());
+    EXPECT_EQ(t.is_val_ref(doc_id), t._p(doc_id)->m_type.is_val_ref());
+    EXPECT_EQ(t.is_val_ref(map_id), t._p(map_id)->m_type.is_val_ref());
+    EXPECT_EQ(t.is_val_ref(keyval_id), t._p(keyval_id)->m_type.is_val_ref());
+    EXPECT_EQ(t.is_val_ref(seq_id), t._p(seq_id)->m_type.is_val_ref());
+    EXPECT_EQ(t.is_val_ref(val_id), t._p(val_id)->m_type.is_val_ref());
+    EXPECT_EQ(stream.is_val_ref(), stream.get()->m_type.is_val_ref());
+    EXPECT_EQ(doc.is_val_ref(), doc.get()->m_type.is_val_ref());
+    EXPECT_EQ(map.is_val_ref(), map.get()->m_type.is_val_ref());
+    EXPECT_EQ(keyval.is_val_ref(), keyval.get()->m_type.is_val_ref());
+    EXPECT_EQ(seq.is_val_ref(), seq.get()->m_type.is_val_ref());
+    EXPECT_EQ(val.is_val_ref(), val.get()->m_type.is_val_ref());
+    EXPECT_EQ(mstream.is_val_ref(), mstream.get()->m_type.is_val_ref());
+    EXPECT_EQ(mdoc.is_val_ref(), mdoc.get()->m_type.is_val_ref());
+    EXPECT_EQ(mmap.is_val_ref(), mmap.get()->m_type.is_val_ref());
+    EXPECT_EQ(mkeyval.is_val_ref(), mkeyval.get()->m_type.is_val_ref());
+    EXPECT_EQ(mseq.is_val_ref(), mseq.get()->m_type.is_val_ref());
+    EXPECT_EQ(mval.is_val_ref(), mval.get()->m_type.is_val_ref());
+}
+
+TEST(NodeType, is_ref)
+{
+    EXPECT_FALSE(NodeType().is_ref());
+    EXPECT_FALSE(NodeType(KEYVAL).is_ref());
+    EXPECT_TRUE(NodeType(KEYREF).is_ref());
+    EXPECT_TRUE(NodeType(VALREF).is_ref());
+    EXPECT_TRUE(NodeType(KEY|VALREF).is_ref());
+    EXPECT_TRUE(NodeType(VAL|KEYREF).is_ref());
+    EXPECT_TRUE(NodeType(KEYREF|VALREF).is_ref());
+}
+
+TEST(Tree, is_ref)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: *keyvalref, notag: none}
+seq: [*valref, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    EXPECT_FALSE(t.is_ref(stream_id));
+    EXPECT_FALSE(t.is_ref(doc_id));
+    EXPECT_FALSE(t.is_ref(map_id));
+    EXPECT_TRUE(t.is_ref(keyval_id));
+    EXPECT_FALSE(t.is_ref(seq_id));
+    EXPECT_TRUE(t.is_ref(val_id));
+    EXPECT_FALSE(stream.is_ref());
+    EXPECT_FALSE(doc.is_ref());
+    EXPECT_FALSE(map.is_ref());
+    EXPECT_TRUE(keyval.is_ref());
+    EXPECT_FALSE(seq.is_ref());
+    EXPECT_TRUE(val.is_ref());
+    EXPECT_FALSE(mstream.is_ref());
+    EXPECT_FALSE(mdoc.is_ref());
+    EXPECT_FALSE(mmap.is_ref());
+    EXPECT_TRUE(mkeyval.is_ref());
+    EXPECT_FALSE(mseq.is_ref());
+    EXPECT_TRUE(mval.is_ref());
+    EXPECT_EQ(t.is_ref(stream_id), t._p(stream_id)->m_type.is_ref());
+    EXPECT_EQ(t.is_ref(doc_id), t._p(doc_id)->m_type.is_ref());
+    EXPECT_EQ(t.is_ref(map_id), t._p(map_id)->m_type.is_ref());
+    EXPECT_EQ(t.is_ref(keyval_id), t._p(keyval_id)->m_type.is_ref());
+    EXPECT_EQ(t.is_ref(seq_id), t._p(seq_id)->m_type.is_ref());
+    EXPECT_EQ(t.is_ref(val_id), t._p(val_id)->m_type.is_ref());
+    EXPECT_EQ(stream.is_ref(), stream.get()->m_type.is_ref());
+    EXPECT_EQ(doc.is_ref(), doc.get()->m_type.is_ref());
+    EXPECT_EQ(map.is_ref(), map.get()->m_type.is_ref());
+    EXPECT_EQ(keyval.is_ref(), keyval.get()->m_type.is_ref());
+    EXPECT_EQ(seq.is_ref(), seq.get()->m_type.is_ref());
+    EXPECT_EQ(val.is_ref(), val.get()->m_type.is_ref());
+    EXPECT_EQ(mstream.is_ref(), mstream.get()->m_type.is_ref());
+    EXPECT_EQ(mdoc.is_ref(), mdoc.get()->m_type.is_ref());
+    EXPECT_EQ(mmap.is_ref(), mmap.get()->m_type.is_ref());
+    EXPECT_EQ(mkeyval.is_ref(), mkeyval.get()->m_type.is_ref());
+    EXPECT_EQ(mseq.is_ref(), mseq.get()->m_type.is_ref());
+    EXPECT_EQ(mval.is_ref(), mval.get()->m_type.is_ref());
+}
+
+TEST(NodeType, is_anchor_or_ref)
+{
+    EXPECT_FALSE(NodeType().is_anchor_or_ref());
+    EXPECT_FALSE(NodeType(KEYVAL).is_anchor_or_ref());
+    EXPECT_TRUE(NodeType(KEYREF).is_anchor_or_ref());
+    EXPECT_TRUE(NodeType(KEYANCH).is_anchor_or_ref());
+    EXPECT_TRUE(NodeType(VALREF).is_anchor_or_ref());
+    EXPECT_TRUE(NodeType(VALANCH).is_anchor_or_ref());
+    EXPECT_TRUE(NodeType(KEY|VALREF).is_anchor_or_ref());
+    EXPECT_TRUE(NodeType(KEY|VALANCH).is_anchor_or_ref());
+    EXPECT_TRUE(NodeType(VAL|KEYREF).is_anchor_or_ref());
+    EXPECT_TRUE(NodeType(VAL|VALANCH).is_anchor_or_ref());
+    EXPECT_TRUE(NodeType(KEY|VALANCH).is_anchor_or_ref());
+    EXPECT_TRUE(NodeType(KEYREF|VALREF).is_anchor_or_ref());
+    EXPECT_TRUE(NodeType(KEYANCH|VALANCH).is_anchor_or_ref());
+}
+
+TEST(Tree, is_anchor_or_ref)
+{
+    Tree t = parse_in_arena(R"(---
+&map map: {foo: *keyvalref, notag: none}
+seq: &seq [*valref, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    EXPECT_FALSE(t.is_anchor_or_ref(stream_id));
+    EXPECT_FALSE(t.is_anchor_or_ref(doc_id));
+    EXPECT_TRUE(t.is_anchor_or_ref(map_id));
+    EXPECT_TRUE(t.is_anchor_or_ref(keyval_id));
+    EXPECT_TRUE(t.is_anchor_or_ref(seq_id));
+    EXPECT_TRUE(t.is_anchor_or_ref(val_id));
+    EXPECT_FALSE(stream.is_anchor_or_ref());
+    EXPECT_FALSE(doc.is_anchor_or_ref());
+    EXPECT_TRUE(map.is_anchor_or_ref());
+    EXPECT_TRUE(keyval.is_anchor_or_ref());
+    EXPECT_TRUE(seq.is_anchor_or_ref());
+    EXPECT_TRUE(val.is_anchor_or_ref());
+    EXPECT_FALSE(mstream.is_anchor_or_ref());
+    EXPECT_FALSE(mdoc.is_anchor_or_ref());
+    EXPECT_TRUE(mmap.is_anchor_or_ref());
+    EXPECT_TRUE(mkeyval.is_anchor_or_ref());
+    EXPECT_TRUE(mseq.is_anchor_or_ref());
+    EXPECT_TRUE(mval.is_anchor_or_ref());
+    EXPECT_EQ(t.is_anchor_or_ref(stream_id), t._p(stream_id)->m_type.is_anchor_or_ref());
+    EXPECT_EQ(t.is_anchor_or_ref(doc_id), t._p(doc_id)->m_type.is_anchor_or_ref());
+    EXPECT_EQ(t.is_anchor_or_ref(map_id), t._p(map_id)->m_type.is_anchor_or_ref());
+    EXPECT_EQ(t.is_anchor_or_ref(keyval_id), t._p(keyval_id)->m_type.is_anchor_or_ref());
+    EXPECT_EQ(t.is_anchor_or_ref(seq_id), t._p(seq_id)->m_type.is_anchor_or_ref());
+    EXPECT_EQ(t.is_anchor_or_ref(val_id), t._p(val_id)->m_type.is_anchor_or_ref());
+    EXPECT_EQ(stream.is_anchor_or_ref(), stream.get()->m_type.is_anchor_or_ref());
+    EXPECT_EQ(doc.is_anchor_or_ref(), doc.get()->m_type.is_anchor_or_ref());
+    EXPECT_EQ(map.is_anchor_or_ref(), map.get()->m_type.is_anchor_or_ref());
+    EXPECT_EQ(keyval.is_anchor_or_ref(), keyval.get()->m_type.is_anchor_or_ref());
+    EXPECT_EQ(seq.is_anchor_or_ref(), seq.get()->m_type.is_anchor_or_ref());
+    EXPECT_EQ(val.is_anchor_or_ref(), val.get()->m_type.is_anchor_or_ref());
+    EXPECT_EQ(mstream.is_anchor_or_ref(), mstream.get()->m_type.is_anchor_or_ref());
+    EXPECT_EQ(mdoc.is_anchor_or_ref(), mdoc.get()->m_type.is_anchor_or_ref());
+    EXPECT_EQ(mmap.is_anchor_or_ref(), mmap.get()->m_type.is_anchor_or_ref());
+    EXPECT_EQ(mkeyval.is_anchor_or_ref(), mkeyval.get()->m_type.is_anchor_or_ref());
+    EXPECT_EQ(mseq.is_anchor_or_ref(), mseq.get()->m_type.is_anchor_or_ref());
+    EXPECT_EQ(mval.is_anchor_or_ref(), mval.get()->m_type.is_anchor_or_ref());
+}
+
+TEST(NodeType, is_key_quoted)
+{
+    EXPECT_FALSE(NodeType().is_key_quoted());
+    EXPECT_FALSE(NodeType(KEYQUO).is_key_quoted());
+    EXPECT_TRUE(NodeType(KEY|KEYQUO).is_key_quoted());
+}
+
+TEST(Tree, is_key_quoted)
+{
+    Tree t = parse_in_arena(R"(---
+"quoted": foo
+notquoted: bar
+...)");
+    const size_t map_id = t.first_child(t.root_id());
+    const size_t quoted_id = t.first_child(map_id);
+    const size_t notquoted_id = t.last_child(map_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef quoted = t.ref(quoted_id);
+    ConstNodeRef notquoted = t.ref(notquoted_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mquoted = t.ref(quoted_id);
+    NodeRef mnotquoted = t.ref(notquoted_id);
+    EXPECT_FALSE(t.is_key_quoted(map_id));
+    EXPECT_TRUE(t.is_key_quoted(quoted_id));
+    EXPECT_FALSE(t.is_key_quoted(notquoted_id));
+    EXPECT_FALSE(map.is_key_quoted());
+    EXPECT_TRUE(quoted.is_key_quoted());
+    EXPECT_FALSE(notquoted.is_key_quoted());
+    EXPECT_FALSE(mmap.is_key_quoted());
+    EXPECT_TRUE(mquoted.is_key_quoted());
+    EXPECT_FALSE(mnotquoted.is_key_quoted());
+    EXPECT_EQ(t.is_key_quoted(map_id), t._p(map_id)->m_type.is_key_quoted());
+    EXPECT_EQ(t.is_key_quoted(quoted_id), t._p(quoted_id)->m_type.is_key_quoted());
+    EXPECT_EQ(t.is_key_quoted(notquoted_id), t._p(notquoted_id)->m_type.is_key_quoted());
+    EXPECT_EQ(map.is_key_quoted(), map.get()->m_type.is_key_quoted());
+    EXPECT_EQ(quoted.is_key_quoted(), quoted.get()->m_type.is_key_quoted());
+    EXPECT_EQ(notquoted.is_key_quoted(), notquoted.get()->m_type.is_key_quoted());
+    EXPECT_EQ(mmap.is_key_quoted(), mmap.get()->m_type.is_key_quoted());
+    EXPECT_EQ(mquoted.is_key_quoted(), mquoted.get()->m_type.is_key_quoted());
+    EXPECT_EQ(mnotquoted.is_key_quoted(), mnotquoted.get()->m_type.is_key_quoted());
+}
+
+TEST(NodeType, is_val_quoted)
+{
+    EXPECT_FALSE(NodeType().is_val_quoted());
+    EXPECT_FALSE(NodeType(VALQUO).is_val_quoted());
+    EXPECT_TRUE(NodeType(VAL|VALQUO).is_val_quoted());
+}
+
+TEST(Tree, is_val_quoted)
+{
+    Tree t = parse_in_arena(R"(---
+"quoted": "foo"
+notquoted: bar
+...)");
+    const size_t map_id = t.first_child(t.root_id());
+    const size_t quoted_id = t.first_child(map_id);
+    const size_t notquoted_id = t.last_child(map_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef quoted = t.ref(quoted_id);
+    ConstNodeRef notquoted = t.ref(notquoted_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mquoted = t.ref(quoted_id);
+    NodeRef mnotquoted = t.ref(notquoted_id);
+    EXPECT_FALSE(t.is_val_quoted(map_id));
+    EXPECT_TRUE(t.is_val_quoted(quoted_id));
+    EXPECT_FALSE(t.is_val_quoted(notquoted_id));
+    EXPECT_FALSE(map.is_val_quoted());
+    EXPECT_TRUE(quoted.is_val_quoted());
+    EXPECT_FALSE(notquoted.is_val_quoted());
+    EXPECT_FALSE(mmap.is_val_quoted());
+    EXPECT_TRUE(mquoted.is_val_quoted());
+    EXPECT_FALSE(mnotquoted.is_val_quoted());
+    EXPECT_EQ(t.is_val_quoted(map_id), t._p(map_id)->m_type.is_val_quoted());
+    EXPECT_EQ(t.is_val_quoted(quoted_id), t._p(quoted_id)->m_type.is_val_quoted());
+    EXPECT_EQ(t.is_val_quoted(notquoted_id), t._p(notquoted_id)->m_type.is_val_quoted());
+    EXPECT_EQ(map.is_val_quoted(), map.get()->m_type.is_val_quoted());
+    EXPECT_EQ(quoted.is_val_quoted(), quoted.get()->m_type.is_val_quoted());
+    EXPECT_EQ(notquoted.is_val_quoted(), notquoted.get()->m_type.is_val_quoted());
+    EXPECT_EQ(mmap.is_val_quoted(), mmap.get()->m_type.is_val_quoted());
+    EXPECT_EQ(mquoted.is_val_quoted(), mquoted.get()->m_type.is_val_quoted());
+    EXPECT_EQ(mnotquoted.is_val_quoted(), mnotquoted.get()->m_type.is_val_quoted());
+}
+
+TEST(NodeType, is_quoted)
+{
+    EXPECT_FALSE(NodeType().is_quoted());
+    EXPECT_FALSE(NodeType(KEYQUO).is_quoted());
+    EXPECT_FALSE(NodeType(VALQUO).is_quoted());
+    EXPECT_FALSE(NodeType(KEYQUO|VALQUO).is_quoted());
+    EXPECT_TRUE(NodeType(KEY|KEYQUO).is_quoted());
+    EXPECT_TRUE(NodeType(VAL|VALQUO).is_quoted());
+    EXPECT_FALSE(NodeType(KEY|VALQUO).is_quoted());
+    EXPECT_FALSE(NodeType(VAL|KEYQUO).is_quoted());
+}
+
+TEST(Tree, is_quoted)
+{
+    Tree t = parse_in_arena(R"(---
+"quoted1": foo
+quoted2: "foo"
+"quoted3": "foo"
+'quoted4': foo
+quoted5: 'foo'
+'quoted6': 'foo'
+notquoted: bar
+...)");
+    const size_t map_id = t.first_child(t.root_id());
+    const size_t quoted1_id = t.find_child(map_id, "quoted1");
+    const size_t quoted2_id = t.find_child(map_id, "quoted2");
+    const size_t quoted3_id = t.find_child(map_id, "quoted3");
+    const size_t quoted4_id = t.find_child(map_id, "quoted4");
+    const size_t quoted5_id = t.find_child(map_id, "quoted5");
+    const size_t quoted6_id = t.find_child(map_id, "quoted6");
+    const size_t notquoted_id = t.last_child(map_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef quoted1 = t.ref(quoted1_id);
+    ConstNodeRef quoted2 = t.ref(quoted2_id);
+    ConstNodeRef quoted3 = t.ref(quoted3_id);
+    ConstNodeRef quoted4 = t.ref(quoted4_id);
+    ConstNodeRef quoted5 = t.ref(quoted5_id);
+    ConstNodeRef quoted6 = t.ref(quoted6_id);
+    ConstNodeRef notquoted = t.ref(notquoted_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mquoted1 = t.ref(quoted1_id);
+    NodeRef mquoted2 = t.ref(quoted2_id);
+    NodeRef mquoted3 = t.ref(quoted3_id);
+    NodeRef mquoted4 = t.ref(quoted4_id);
+    NodeRef mquoted5 = t.ref(quoted5_id);
+    NodeRef mquoted6 = t.ref(quoted6_id);
+    NodeRef mnotquoted = t.ref(notquoted_id);
+    EXPECT_FALSE(t.is_quoted(map_id));
+    EXPECT_TRUE(t.is_quoted(quoted1_id));
+    EXPECT_TRUE(t.is_quoted(quoted2_id));
+    EXPECT_TRUE(t.is_quoted(quoted3_id));
+    EXPECT_TRUE(t.is_quoted(quoted4_id));
+    EXPECT_TRUE(t.is_quoted(quoted5_id));
+    EXPECT_TRUE(t.is_quoted(quoted6_id));
+    EXPECT_FALSE(t.is_quoted(notquoted_id));
+    EXPECT_FALSE(map.is_quoted());
+    EXPECT_TRUE(quoted1.is_quoted());
+    EXPECT_TRUE(quoted2.is_quoted());
+    EXPECT_TRUE(quoted3.is_quoted());
+    EXPECT_TRUE(quoted4.is_quoted());
+    EXPECT_TRUE(quoted5.is_quoted());
+    EXPECT_TRUE(quoted6.is_quoted());
+    EXPECT_FALSE(notquoted.is_quoted());
+    EXPECT_FALSE(mmap.is_quoted());
+    EXPECT_TRUE(mquoted1.is_quoted());
+    EXPECT_TRUE(mquoted2.is_quoted());
+    EXPECT_TRUE(mquoted3.is_quoted());
+    EXPECT_TRUE(mquoted4.is_quoted());
+    EXPECT_TRUE(mquoted5.is_quoted());
+    EXPECT_TRUE(mquoted6.is_quoted());
+    EXPECT_FALSE(mnotquoted.is_quoted());
+    EXPECT_EQ(t.is_quoted(map_id), t._p(map_id)->m_type.is_quoted());
+    EXPECT_EQ(t.is_quoted(quoted1_id), t._p(quoted1_id)->m_type.is_quoted());
+    EXPECT_EQ(t.is_quoted(quoted2_id), t._p(quoted2_id)->m_type.is_quoted());
+    EXPECT_EQ(t.is_quoted(quoted3_id), t._p(quoted3_id)->m_type.is_quoted());
+    EXPECT_EQ(t.is_quoted(quoted4_id), t._p(quoted4_id)->m_type.is_quoted());
+    EXPECT_EQ(t.is_quoted(quoted5_id), t._p(quoted5_id)->m_type.is_quoted());
+    EXPECT_EQ(t.is_quoted(quoted6_id), t._p(quoted6_id)->m_type.is_quoted());
+    EXPECT_EQ(t.is_quoted(notquoted_id), t._p(notquoted_id)->m_type.is_quoted());
+    EXPECT_EQ(map.is_quoted(), map.get()->m_type.is_quoted());
+    EXPECT_EQ(quoted1.is_quoted(), quoted1.get()->m_type.is_quoted());
+    EXPECT_EQ(quoted2.is_quoted(), quoted2.get()->m_type.is_quoted());
+    EXPECT_EQ(quoted3.is_quoted(), quoted3.get()->m_type.is_quoted());
+    EXPECT_EQ(quoted4.is_quoted(), quoted4.get()->m_type.is_quoted());
+    EXPECT_EQ(quoted5.is_quoted(), quoted5.get()->m_type.is_quoted());
+    EXPECT_EQ(quoted6.is_quoted(), quoted6.get()->m_type.is_quoted());
+    EXPECT_EQ(notquoted.is_quoted(), notquoted.get()->m_type.is_quoted());
+    EXPECT_EQ(mmap.is_quoted(), mmap.get()->m_type.is_quoted());
+    EXPECT_EQ(mquoted1.is_quoted(), mquoted1.get()->m_type.is_quoted());
+    EXPECT_EQ(mquoted2.is_quoted(), mquoted2.get()->m_type.is_quoted());
+    EXPECT_EQ(mquoted3.is_quoted(), mquoted3.get()->m_type.is_quoted());
+    EXPECT_EQ(mquoted4.is_quoted(), mquoted4.get()->m_type.is_quoted());
+    EXPECT_EQ(mquoted5.is_quoted(), mquoted5.get()->m_type.is_quoted());
+    EXPECT_EQ(mquoted6.is_quoted(), mquoted6.get()->m_type.is_quoted());
+    EXPECT_EQ(mnotquoted.is_quoted(), mnotquoted.get()->m_type.is_quoted());
+}
+
+
+TEST(Tree, parent_is_seq)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: *keyvalref, notag: none}
+seq: &seq [*valref, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    //EXPECT_FALSE(t.parent_is_seq(stream_id));
+    EXPECT_TRUE(t.parent_is_seq(doc_id));
+    EXPECT_FALSE(t.parent_is_seq(map_id));
+    EXPECT_FALSE(t.parent_is_seq(keyval_id));
+    EXPECT_FALSE(t.parent_is_seq(seq_id));
+    EXPECT_TRUE(t.parent_is_seq(val_id));
+    //EXPECT_FALSE(stream.parent_is_seq());
+    EXPECT_TRUE(doc.parent_is_seq());
+    EXPECT_FALSE(map.parent_is_seq());
+    EXPECT_FALSE(keyval.parent_is_seq());
+    EXPECT_FALSE(seq.parent_is_seq());
+    EXPECT_TRUE(val.parent_is_seq());
+    //EXPECT_FALSE(mstream.parent_is_seq());
+    EXPECT_TRUE(mdoc.parent_is_seq());
+    EXPECT_FALSE(mmap.parent_is_seq());
+    EXPECT_FALSE(mkeyval.parent_is_seq());
+    EXPECT_FALSE(mseq.parent_is_seq());
+    EXPECT_TRUE(mval.parent_is_seq());
+    //EXPECT_EQ(t.parent_is_seq(stream_id), stream.parent_is_seq());
+    EXPECT_EQ(t.parent_is_seq(doc_id), doc.parent_is_seq());
+    EXPECT_EQ(t.parent_is_seq(map_id), map.parent_is_seq());
+    EXPECT_EQ(t.parent_is_seq(keyval_id), keyval.parent_is_seq());
+    EXPECT_EQ(t.parent_is_seq(seq_id), seq.parent_is_seq());
+    EXPECT_EQ(t.parent_is_seq(val_id), val.parent_is_seq());
+    EXPECT_EQ(t.parent_is_seq(doc_id), mdoc.parent_is_seq());
+    EXPECT_EQ(t.parent_is_seq(map_id), mmap.parent_is_seq());
+    EXPECT_EQ(t.parent_is_seq(keyval_id), mkeyval.parent_is_seq());
+    EXPECT_EQ(t.parent_is_seq(seq_id), mseq.parent_is_seq());
+    EXPECT_EQ(t.parent_is_seq(val_id), mval.parent_is_seq());
+}
+
+TEST(Tree, parent_is_map)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: *keyvalref, notag: none}
+seq: &seq [*valref, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    //EXPECT_FALSE(t.parent_is_map(stream_id));
+    EXPECT_FALSE(t.parent_is_map(doc_id));
+    EXPECT_TRUE(t.parent_is_map(map_id));
+    EXPECT_TRUE(t.parent_is_map(keyval_id));
+    EXPECT_TRUE(t.parent_is_map(seq_id));
+    EXPECT_FALSE(t.parent_is_map(val_id));
+    //EXPECT_FALSE(stream.parent_is_map());
+    EXPECT_FALSE(doc.parent_is_map());
+    EXPECT_TRUE(map.parent_is_map());
+    EXPECT_TRUE(keyval.parent_is_map());
+    EXPECT_TRUE(seq.parent_is_map());
+    EXPECT_FALSE(val.parent_is_map());
+    //EXPECT_FALSE(mstream.parent_is_map());
+    EXPECT_FALSE(mdoc.parent_is_map());
+    EXPECT_TRUE(mmap.parent_is_map());
+    EXPECT_TRUE(mkeyval.parent_is_map());
+    EXPECT_TRUE(mseq.parent_is_map());
+    EXPECT_FALSE(mval.parent_is_map());
+    //EXPECT_EQ(t.parent_is_map(stream_id), stream.parent_is_map());
+    EXPECT_EQ(t.parent_is_map(doc_id), doc.parent_is_map());
+    EXPECT_EQ(t.parent_is_map(map_id), map.parent_is_map());
+    EXPECT_EQ(t.parent_is_map(keyval_id), keyval.parent_is_map());
+    EXPECT_EQ(t.parent_is_map(seq_id), seq.parent_is_map());
+    EXPECT_EQ(t.parent_is_map(val_id), val.parent_is_map());
+    //EXPECT_EQ(t.parent_is_map(stream_id), mstream.parent_is_map());
+    EXPECT_EQ(t.parent_is_map(doc_id), mdoc.parent_is_map());
+    EXPECT_EQ(t.parent_is_map(map_id), mmap.parent_is_map());
+    EXPECT_EQ(t.parent_is_map(keyval_id), mkeyval.parent_is_map());
+    EXPECT_EQ(t.parent_is_map(seq_id), mseq.parent_is_map());
+    EXPECT_EQ(t.parent_is_map(val_id), mval.parent_is_map());
+}
+
+TEST(Tree, has_parent)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: *keyvalref, notag: none}
+seq: &seq [*valref, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    EXPECT_FALSE(t.has_parent(stream_id));
+    EXPECT_TRUE(t.has_parent(doc_id));
+    EXPECT_TRUE(t.has_parent(map_id));
+    EXPECT_TRUE(t.has_parent(keyval_id));
+    EXPECT_TRUE(t.has_parent(seq_id));
+    EXPECT_TRUE(t.has_parent(val_id));
+    EXPECT_FALSE(stream.has_parent());
+    EXPECT_TRUE(doc.has_parent());
+    EXPECT_TRUE(map.has_parent());
+    EXPECT_TRUE(keyval.has_parent());
+    EXPECT_TRUE(seq.has_parent());
+    EXPECT_TRUE(val.has_parent());
+    EXPECT_FALSE(mstream.has_parent());
+    EXPECT_TRUE(mdoc.has_parent());
+    EXPECT_TRUE(mmap.has_parent());
+    EXPECT_TRUE(mkeyval.has_parent());
+    EXPECT_TRUE(mseq.has_parent());
+    EXPECT_TRUE(mval.has_parent());
+    EXPECT_EQ(t.has_parent(stream_id), stream.has_parent());
+    EXPECT_EQ(t.has_parent(doc_id), doc.has_parent());
+    EXPECT_EQ(t.has_parent(map_id), map.has_parent());
+    EXPECT_EQ(t.has_parent(keyval_id), keyval.has_parent());
+    EXPECT_EQ(t.has_parent(seq_id), seq.has_parent());
+    EXPECT_EQ(t.has_parent(val_id), val.has_parent());
+    EXPECT_EQ(t.has_parent(stream_id), mstream.has_parent());
+    EXPECT_EQ(t.has_parent(doc_id), mdoc.has_parent());
+    EXPECT_EQ(t.has_parent(map_id), mmap.has_parent());
+    EXPECT_EQ(t.has_parent(keyval_id), mkeyval.has_parent());
+    EXPECT_EQ(t.has_parent(seq_id), mseq.has_parent());
+    EXPECT_EQ(t.has_parent(val_id), mval.has_parent());
+}
+
+
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+TEST(Tree, num_children)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: *keyvalref, notag: none}
+seq: &seq [*valref, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    EXPECT_EQ(t.num_children(stream_id), 1u);
+    EXPECT_EQ(t.num_children(doc_id), 2u);
+    EXPECT_EQ(t.num_children(map_id), 2u);
+    EXPECT_EQ(t.num_children(keyval_id), 0u);
+    EXPECT_EQ(t.num_children(seq_id), 2u);
+    EXPECT_EQ(t.num_children(val_id), 0u);
+    EXPECT_EQ(stream.num_children(), t.num_children(stream_id));
+    EXPECT_EQ(doc.num_children(), t.num_children(doc_id));
+    EXPECT_EQ(map.num_children(), t.num_children(map_id));
+    EXPECT_EQ(keyval.num_children(), t.num_children(keyval_id));
+    EXPECT_EQ(seq.num_children(), t.num_children(seq_id));
+    EXPECT_EQ(val.num_children(), t.num_children(val_id));
+    EXPECT_EQ(mstream.num_children(), t.num_children(stream_id));
+    EXPECT_EQ(mdoc.num_children(), t.num_children(doc_id));
+    EXPECT_EQ(mmap.num_children(), t.num_children(map_id));
+    EXPECT_EQ(mkeyval.num_children(), t.num_children(keyval_id));
+    EXPECT_EQ(mseq.num_children(), t.num_children(seq_id));
+    EXPECT_EQ(mval.num_children(), t.num_children(val_id));
+}
+
+TEST(Tree, child)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: *keyvalref, notag: none}
+seq: &seq [*valref, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    const size_t val_id = t.first_child(seq_id);
+    ConstNodeRef stream = t.ref(stream_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    ConstNodeRef keyval = t.ref(keyval_id);
+    ConstNodeRef seq = t.ref(seq_id);
+    ConstNodeRef val = t.ref(val_id);
+    NodeRef mstream = t.ref(stream_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    NodeRef mkeyval = t.ref(keyval_id);
+    NodeRef mseq = t.ref(seq_id);
+    NodeRef mval = t.ref(val_id);
+    EXPECT_EQ(t.child(stream_id, 0), doc_id);
+    EXPECT_EQ(t.child(doc_id, 0), map_id);
+    EXPECT_EQ(t.child(map_id, 0), keyval_id);
+    EXPECT_EQ(t.child(keyval_id, 0), (size_t)NONE);
+    EXPECT_EQ(t.child(seq_id, 0), val_id);
+    EXPECT_EQ(t.child(val_id, 0), (size_t)NONE);
+    EXPECT_EQ(stream.child(0).id(), t.child(stream_id, 0));
+    EXPECT_EQ(doc.child(0).id(), t.child(doc_id, 0));
+    EXPECT_EQ(map.child(0).id(), t.child(map_id, 0));
+    EXPECT_EQ(keyval.child(0).id(), t.child(keyval_id, 0));
+    EXPECT_EQ(seq.child(0).id(), t.child(seq_id, 0));
+    EXPECT_EQ(val.child(0).id(), t.child(val_id, 0));
+    EXPECT_EQ(mstream.child(0).id(), t.child(stream_id, 0));
+    EXPECT_EQ(mdoc.child(0).id(), t.child(doc_id, 0));
+    EXPECT_EQ(mmap.child(0).id(), t.child(map_id, 0));
+    EXPECT_EQ(mkeyval.child(0).id(), t.child(keyval_id, 0));
+    EXPECT_EQ(mseq.child(0).id(), t.child(seq_id, 0));
+    EXPECT_EQ(mval.child(0).id(), t.child(val_id, 0));
+}
+
+TEST(Tree, find_child_by_name)
+{
+    Tree t = parse_in_arena(R"(---
+map: {foo: *keyvalref, notag: none}
+seq: &seq [*valref, bar]
+...)");
+    const size_t stream_id = t.root_id();
+    const size_t doc_id = t.first_child(stream_id);
+    const size_t map_id = t.first_child(doc_id);
+    const size_t keyval_id = t.first_child(map_id);
+    const size_t seq_id = t.last_child(doc_id);
+    ConstNodeRef doc = t.ref(doc_id);
+    ConstNodeRef map = t.ref(map_id);
+    NodeRef mdoc = t.ref(doc_id);
+    NodeRef mmap = t.ref(map_id);
+    EXPECT_EQ(t.find_child(doc_id, "map"), map_id);
+    EXPECT_EQ(t.find_child(doc_id, "seq"), seq_id);
+    EXPECT_EQ(t.find_child(doc_id, "..."), (size_t)NONE);
+    EXPECT_EQ(t.find_child(map_id, "foo"), keyval_id);
+    EXPECT_EQ(t.find_child(map_id, "bar"), (size_t)NONE);
+    EXPECT_EQ(doc.find_child("map").id(), t.find_child(doc_id, "map"));
+    EXPECT_EQ(doc.find_child("seq").id(), t.find_child(doc_id, "seq"));
+    EXPECT_EQ(doc.find_child("...").id(), t.find_child(doc_id, "..."));
+    EXPECT_EQ(map.find_child("foo").id(), t.find_child(map_id, "foo"));
+    EXPECT_EQ(map.find_child("bar").id(), t.find_child(map_id, "bar"));
+    EXPECT_EQ(mdoc.find_child("map").id(), t.find_child(doc_id, "map"));
+    EXPECT_EQ(mdoc.find_child("seq").id(), t.find_child(doc_id, "seq"));
+    EXPECT_EQ(mdoc.find_child("...").id(), t.find_child(doc_id, "..."));
+    EXPECT_EQ(mmap.find_child("foo").id(), t.find_child(map_id, "foo"));
+    EXPECT_EQ(mmap.find_child("bar").id(), t.find_child(map_id, "bar"));
+}
+
+
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+TEST(change_type, from_val)
+{
+    Tree t = parse_in_arena("[val0, val1, val2]");
+    t[0].change_type(VAL);
+    t[1].change_type(MAP);
+    t[2].change_type(SEQ);
+    Tree expected = parse_in_arena("[val0, {}, []]");
+    EXPECT_EQ(emitrs_yaml<std::string>(t), emitrs_yaml<std::string>(expected));
+}
+TEST(change_type, from_keyval)
+{
+    Tree t = parse_in_arena("{keyval0: val0, keyval1: val1, keyval2: val2}");
+    t[0].change_type(VAL);
+    t[1].change_type(MAP);
+    t[2].change_type(SEQ);
+    Tree expected = parse_in_arena("{keyval0: val0, keyval1: {}, keyval2: []}");
+    EXPECT_EQ(emitrs_yaml<std::string>(t), emitrs_yaml<std::string>(expected));
+}
+
+TEST(change_type, from_map)
+{
+    Tree t = parse_in_arena("[{map0: val0}, {map1: {map1key0: a, map1key1: b}}, {map2: [map2val0, map2val1]}]");
+    t[0].change_type(VAL);
+    t[1].change_type(MAP);
+    t[2].change_type(SEQ);
+    EXPECT_FALSE(t[0].val_is_null());
+    EXPECT_NE(t[0].val(), nullptr);
+    Tree expected = parse_in_arena("['', {map1: {map1key0: a, map1key1: b}}, []]");
+    EXPECT_EQ(emitrs_yaml<std::string>(t), emitrs_yaml<std::string>(expected));
+}
+TEST(change_type, from_keymap)
+{
+    Tree t = parse_in_arena("{map0: {map0: val0}, map1: {map1: {map1key0: a, map1key1: b}}, map2: {map2: [map2val0, map2val1]}}");
+    t[0].change_type(VAL);
+    t[1].change_type(MAP);
+    t[2].change_type(SEQ);
+    EXPECT_FALSE(t[0].val_is_null());
+    EXPECT_NE(t[0].val(), nullptr);
+    Tree expected = parse_in_arena("{map0: '', map1: {map1: {map1key0: a, map1key1: b}}, map2: []}");
+    EXPECT_EQ(emitrs_yaml<std::string>(t), emitrs_yaml<std::string>(expected));
+}
+
+TEST(change_type, from_seq)
+{
+    Tree t = parse_in_arena("[[seq00, seq01], [seq10, seq11], [seq20, seq21]]");
+    t[0].change_type(VAL);
+    t[1].change_type(MAP);
+    t[2].change_type(SEQ);
+    EXPECT_FALSE(t[0].val_is_null());
+    EXPECT_NE(t[0].val(), nullptr);
+    Tree expected = parse_in_arena("['', {}, [seq20, seq21]]");
+    EXPECT_EQ(emitrs_yaml<std::string>(t), emitrs_yaml<std::string>(expected));
+}
+TEST(change_type, from_keyseq)
+{
+    Tree t = parse_in_arena("{map0: [seq00, seq01], map1: [seq10, seq11], map2: [seq20, seq21]}");
+    t[0].change_type(VAL);
+    t[1].change_type(MAP);
+    t[2].change_type(SEQ);
+    EXPECT_FALSE(t[0].val_is_null());
+    EXPECT_NE(t[0].val(), nullptr);
+    Tree expected = parse_in_arena("{map0: '', map1: {}, map2: [seq20, seq21]}");
+    EXPECT_EQ(emitrs_yaml<std::string>(t), emitrs_yaml<std::string>(expected));
+}
+
+
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+
+TEST(Tree, lookup_path)
+{
+    const char yaml[] = R"(
+a:
+  b: bval
+  c:
+    d:
+      - e
+      - d
+      - f: fval
+        g: gval
+        h:
+          -
+            x: a
+            y: b
+          -
+            z: c
+            u:
+)";
+    Tree t = parse_in_arena(yaml);
+    print_tree(t);
+
+    EXPECT_EQ(t.lookup_path("a").target, 1);
+    EXPECT_EQ(t.lookup_path("a.b").target, 2);
+    EXPECT_EQ(t.lookup_path("a.c").target, 3);
+    EXPECT_EQ(t.lookup_path("a.c.d").target, 4);
+    EXPECT_EQ(t.lookup_path("a.c.d[0]").target, 5);
+    EXPECT_EQ(t.lookup_path("a.c.d[1]").target, 6);
+    EXPECT_EQ(t.lookup_path("a.c.d[2]").target, 7);
+    EXPECT_EQ(t.lookup_path("a.c.d[2].f").target, 8);
+    EXPECT_EQ(t.lookup_path("a.c.d[2].g").target, 9);
+    EXPECT_EQ(t.lookup_path("a.c.d[2].h").target, 10);
+    EXPECT_EQ(t.lookup_path("a.c.d[2].h[0]").target, 11);
+    EXPECT_EQ(t.lookup_path("a.c.d[2].h[0].x").target, 12);
+    EXPECT_EQ(t.lookup_path("a.c.d[2].h[0].y").target, 13);
+    EXPECT_EQ(t.lookup_path("a.c.d[2].h[1]").target, 14);
+    EXPECT_EQ(t.lookup_path("a.c.d[2].h[1].z").target, 15);
+    EXPECT_EQ(t.lookup_path("a.c.d[2].h[1].u").target, 16);
+    EXPECT_EQ(t.lookup_path("d", 3).target, 4);
+    EXPECT_EQ(t.lookup_path("d[0]", 3).target, 5);
+    EXPECT_EQ(t.lookup_path("d[1]", 3).target, 6);
+    EXPECT_EQ(t.lookup_path("d[2]", 3).target, 7);
+    EXPECT_EQ(t.lookup_path("d[2].f", 3).target, 8);
+    EXPECT_EQ(t.lookup_path("d[2].g", 3).target, 9);
+    EXPECT_EQ(t.lookup_path("d[2].h", 3).target, 10);
+    EXPECT_EQ(t.lookup_path("d[2].h[0]", 3).target, 11);
+    EXPECT_EQ(t.lookup_path("d[2].h[0].x", 3).target, 12);
+    EXPECT_EQ(t.lookup_path("d[2].h[0].y", 3).target, 13);
+    EXPECT_EQ(t.lookup_path("d[2].h[1]", 3).target, 14);
+    EXPECT_EQ(t.lookup_path("d[2].h[1].z", 3).target, 15);
+    EXPECT_EQ(t.lookup_path("d[2].h[1].u", 3).target, 16);
+
+    auto lp = t.lookup_path("x");
+    EXPECT_FALSE(lp);
+    EXPECT_EQ(lp.target, (size_t)NONE);
+    EXPECT_EQ(lp.closest, (size_t)NONE);
+    EXPECT_EQ(lp.resolved(), "");
+    EXPECT_EQ(lp.unresolved(), "x");
+    lp = t.lookup_path("a.x");
+    EXPECT_FALSE(lp);
+    EXPECT_EQ(lp.target, (size_t)NONE);
+    EXPECT_EQ(lp.closest, 1);
+    EXPECT_EQ(lp.resolved(), "a");
+    EXPECT_EQ(lp.unresolved(), "x");
+    lp = t.lookup_path("a.b.x");
+    EXPECT_FALSE(lp);
+    EXPECT_EQ(lp.target, (size_t)NONE);
+    EXPECT_EQ(lp.closest, 2);
+    EXPECT_EQ(lp.resolved(), "a.b");
+    EXPECT_EQ(lp.unresolved(), "x");
+    lp = t.lookup_path("a.c.x");
+    EXPECT_FALSE(lp);
+    EXPECT_EQ(lp.target, (size_t)NONE);
+    EXPECT_EQ(lp.closest, 3);
+    EXPECT_EQ(lp.resolved(), "a.c");
+    EXPECT_EQ(lp.unresolved(), "x");
+
+    size_t sz = t.size();
+    EXPECT_EQ(t.lookup_path("x").target, (size_t)NONE);
+    EXPECT_EQ(t.lookup_path_or_modify("x", "x"), sz);
+    EXPECT_EQ(t.lookup_path("x").target, sz);
+    EXPECT_EQ(t.val(sz), "x");
+    EXPECT_EQ(t.lookup_path_or_modify("y", "x"), sz);
+    EXPECT_EQ(t.val(sz), "y");
+    EXPECT_EQ(t.lookup_path_or_modify("z", "x"), sz);
+    EXPECT_EQ(t.val(sz), "z");
+
+    sz = t.size();
+    EXPECT_EQ(t.lookup_path("a.x").target, (size_t)NONE);
+    EXPECT_EQ(t.lookup_path_or_modify("x", "a.x"), sz);
+    EXPECT_EQ(t.lookup_path("a.x").target, sz);
+    EXPECT_EQ(t.val(sz), "x");
+    EXPECT_EQ(t.lookup_path_or_modify("y", "a.x"), sz);
+    EXPECT_EQ(t.val(sz), "y");
+    EXPECT_EQ(t.lookup_path_or_modify("z", "a.x"), sz);
+    EXPECT_EQ(t.val(sz), "z");
+
+    sz = t.size();
+    EXPECT_EQ(t.lookup_path("a.c.x").target, (size_t)NONE);
+    EXPECT_EQ(t.lookup_path_or_modify("x", "a.c.x"), sz);
+    EXPECT_EQ(t.lookup_path("a.c.x").target, sz);
+    EXPECT_EQ(t.val(sz), "x");
+    EXPECT_EQ(t.lookup_path_or_modify("y", "a.c.x"), sz);
+    EXPECT_EQ(t.val(sz), "y");
+    EXPECT_EQ(t.lookup_path_or_modify("z", "a.c.x"), sz);
+    EXPECT_EQ(t.val(sz), "z");
+}
+
+TEST(Tree, lookup_path_or_modify)
+{
+    {
+        Tree dst = parse_in_arena("{}");
+        Tree const src = parse_in_arena("{d: [x, y, z]}");
+        dst.lookup_path_or_modify("ok", "a.b.c");
+        EXPECT_EQ(dst["a"]["b"]["c"].val(), "ok");
+        dst.lookup_path_or_modify(&src, src["d"].id(), "a.b.d");
+        EXPECT_EQ(dst["a"]["b"]["d"][0].val(), "x");
+        EXPECT_EQ(dst["a"]["b"]["d"][1].val(), "y");
+        EXPECT_EQ(dst["a"]["b"]["d"][2].val(), "z");
+    }
+
+    {
+        Tree t = parse_in_arena("{}");
+        csubstr bigpath = "newmap.newseq[0].newmap.newseq[0].first";
+        auto result = t.lookup_path(bigpath);
+        EXPECT_EQ(result.target, (size_t)NONE);
+        EXPECT_EQ(result.closest, (size_t)NONE);
+        EXPECT_EQ(result.resolved(), "");
+        EXPECT_EQ(result.unresolved(), bigpath);
+        size_t sz = t.lookup_path_or_modify("x", bigpath);
+        EXPECT_EQ(t.lookup_path(bigpath).target, sz);
+        EXPECT_EQ(t.val(sz), "x");
+        EXPECT_EQ(t["newmap"]["newseq"].num_children(), 1u);
+        EXPECT_EQ(t["newmap"]["newseq"][0].is_map(), true);
+        EXPECT_EQ(t["newmap"]["newseq"][0]["newmap"].is_map(), true);
+        EXPECT_EQ(t["newmap"]["newseq"][0]["newmap"]["newseq"].is_seq(), true);
+        EXPECT_EQ(t["newmap"]["newseq"][0]["newmap"]["newseq"].num_children(), 1u);
+        EXPECT_EQ(t["newmap"]["newseq"][0]["newmap"]["newseq"][0].is_map(), true);
+        EXPECT_EQ(t["newmap"]["newseq"][0]["newmap"]["newseq"][0]["first"].val(), "x");
+        size_t sz2 = t.lookup_path_or_modify("y", bigpath);
+        EXPECT_EQ(t["newmap"]["newseq"][0]["newmap"]["newseq"][0]["first"].val(), "y");
+        EXPECT_EQ(sz2, sz);
+        EXPECT_EQ(t.lookup_path(bigpath).target, sz);
+        EXPECT_EQ(t.val(sz2), "y");
+
+        sz2 = t.lookup_path_or_modify("y", "newmap2.newseq2[2].newmap2.newseq2[3].first2");
+        EXPECT_EQ(t.lookup_path("newmap2.newseq2[2].newmap2.newseq2[3].first2").target, sz2);
+        EXPECT_EQ(t.val(sz2), "y");
+        EXPECT_EQ(t["newmap2"]["newseq2"].num_children(), 3u);
+        EXPECT_EQ(t["newmap2"]["newseq2"][0].val(), nullptr);
+        EXPECT_EQ(t["newmap2"]["newseq2"][1].val(), nullptr);
+        EXPECT_EQ(t["newmap2"]["newseq2"][2].is_map(), true);
+        EXPECT_EQ(t["newmap2"]["newseq2"][2]["newmap2"].is_map(), true);
+        EXPECT_EQ(t["newmap2"]["newseq2"][2]["newmap2"]["newseq2"].is_seq(), true);
+        EXPECT_EQ(t["newmap2"]["newseq2"][2]["newmap2"]["newseq2"].num_children(), 4u);
+        EXPECT_EQ(t["newmap2"]["newseq2"][2]["newmap2"]["newseq2"][0].val(), nullptr);
+        EXPECT_EQ(t["newmap2"]["newseq2"][2]["newmap2"]["newseq2"][1].val(), nullptr);
+        EXPECT_EQ(t["newmap2"]["newseq2"][2]["newmap2"]["newseq2"][2].val(), nullptr);
+        EXPECT_EQ(t["newmap2"]["newseq2"][2]["newmap2"]["newseq2"][3].is_map(), true);
+        EXPECT_EQ(t["newmap2"]["newseq2"][2]["newmap2"]["newseq2"][3]["first2"].val(), "y");
+        sz2 = t.lookup_path_or_modify("z", "newmap2.newseq2[2].newmap2.newseq2[3].second2");
+        EXPECT_EQ  (t["newmap2"]["newseq2"][2]["newmap2"]["newseq2"][3]["second2"].val(), "z");
+
+        sz = t.lookup_path_or_modify("foo", "newmap.newseq1[1]");
+        EXPECT_EQ(t["newmap"].is_map(), true);
+        EXPECT_EQ(t["newmap"]["newseq1"].is_seq(), true);
+        EXPECT_EQ(t["newmap"]["newseq1"].num_children(), 2u);
+        EXPECT_EQ(t["newmap"]["newseq1"][0].val(), nullptr);
+        EXPECT_EQ(t["newmap"]["newseq1"][1].val(), "foo");
+        sz = t.lookup_path_or_modify("bar", "newmap.newseq1[2][1]");
+        EXPECT_EQ(t["newmap"]["newseq1"].is_seq(), true);
+        EXPECT_EQ(t["newmap"]["newseq1"].num_children(), 3u);
+        EXPECT_EQ(t["newmap"]["newseq1"][0].val(), nullptr);
+        EXPECT_EQ(t["newmap"]["newseq1"][1].val(), "foo");
+        EXPECT_EQ(t["newmap"]["newseq1"][2].is_seq(), true);
+        EXPECT_EQ(t["newmap"]["newseq1"][2].num_children(), 2u);
+        EXPECT_EQ(t["newmap"]["newseq1"][2][0].val(), nullptr);
+        EXPECT_EQ(t["newmap"]["newseq1"][2][1].val(), "bar");
+        sz = t.lookup_path_or_modify("Foo?"   , "newmap.newseq1[0]");
+        sz = t.lookup_path_or_modify("Bar?"   , "newmap.newseq1[2][0]");
+        sz = t.lookup_path_or_modify("happy"  , "newmap.newseq1[2][2][3]");
+        sz = t.lookup_path_or_modify("trigger", "newmap.newseq1[2][2][2]");
+        sz = t.lookup_path_or_modify("Arnold" , "newmap.newseq1[2][2][0]");
+        sz = t.lookup_path_or_modify("is"     , "newmap.newseq1[2][2][1]");
+        EXPECT_EQ(t["newmap"]["newseq1"].is_seq(), true);
+        EXPECT_EQ(t["newmap"]["newseq1"].num_children(), 3u);
+        EXPECT_EQ(t["newmap"]["newseq1"][0].val(), "Foo?");
+        EXPECT_EQ(t["newmap"]["newseq1"][1].val(), "foo");
+        EXPECT_EQ(t["newmap"]["newseq1"][2].is_seq(), true);
+        EXPECT_EQ(t["newmap"]["newseq1"][2].num_children(), 3u);
+        EXPECT_EQ(t["newmap"]["newseq1"][2][0].val(), "Bar?");
+        EXPECT_EQ(t["newmap"]["newseq1"][2][1].val(), "bar");
+        EXPECT_EQ(t["newmap"]["newseq1"][2][2].is_seq(), true);
+        EXPECT_EQ(t["newmap"]["newseq1"][2][2].num_children(), 4u);
+        EXPECT_EQ(t["newmap"]["newseq1"][2][2][0].val(), "Arnold");
+        EXPECT_EQ(t["newmap"]["newseq1"][2][2][1].val(), "is");
+        EXPECT_EQ(t["newmap"]["newseq1"][2][2][2].val(), "trigger");
+        EXPECT_EQ(t["newmap"]["newseq1"][2][2][3].val(), "happy");
+
+        EXPECT_EQ(emitrs_yaml<std::string>(t), R"(newmap:
+  newseq:
+    - newmap:
+        newseq:
+          - first: y
+  newseq1:
+    - 'Foo?'
+    - foo
+    - - 'Bar?'
+      - bar
+      - - Arnold
+        - is
+        - trigger
+        - happy
+newmap2:
+  newseq2:
+    - 
+    - 
+    - newmap2:
+        newseq2:
+          - 
+          - 
+          - 
+          - first2: y
+            second2: z
+)");
+    }
+}
+
+
+
+//-----------------------------------------------------------------------------
+
+TEST(set_root_as_stream, empty_tree)
+{
+    Tree t;
+    NodeRef r = t.rootref();
+    EXPECT_EQ(r.is_stream(), false);
+    EXPECT_EQ(r.num_children(), 0u);
+    t.set_root_as_stream();
+    EXPECT_EQ(r.is_stream(), true);
+    EXPECT_EQ(r.num_children(), 0u);
+}
+
+TEST(set_root_as_stream, already_with_stream)
+{
+    Tree t;
+    t.to_stream(t.root_id());
+    NodeRef r = t.rootref();
+    EXPECT_EQ(r.is_stream(), true);
+    EXPECT_EQ(r.num_children(), 0u);
+    t.set_root_as_stream();
+    EXPECT_EQ(r.is_stream(), true);
+    EXPECT_EQ(r.num_children(), 0u);
+}
+
+
+TEST(set_root_as_stream, root_is_map)
+{
+    Tree t = parse_in_arena(R"({a: b, c: d})");
+    NodeRef r = t.rootref();
+    EXPECT_EQ(r.is_stream(), false);
+    EXPECT_EQ(r.is_doc(), false);
+    EXPECT_EQ(r.is_map(), true);
+    EXPECT_EQ(r.is_seq(), false);
+    EXPECT_EQ(r.num_children(), 2u);
+    print_tree(t);
+    std::cout << t;
+    t.set_root_as_stream();
+    print_tree(t);
+    std::cout << t;
+    EXPECT_EQ(r.is_stream(), true);
+    EXPECT_EQ(r.is_doc(), false);
+    EXPECT_EQ(r.is_map(), false);
+    EXPECT_EQ(r.is_seq(), true);
+    EXPECT_EQ(r.num_children(), 1u);
+    EXPECT_EQ(r[0].is_doc(), true);
+    EXPECT_EQ(r[0].is_map(), true);
+    EXPECT_EQ(r[0].is_seq(), false);
+    EXPECT_EQ(r[0].num_children(), 2u);
+    EXPECT_EQ(r[0]["a"].is_keyval(), true);
+    EXPECT_EQ(r[0]["c"].is_keyval(), true);
+    EXPECT_EQ(r[0]["a"].val(), "b");
+    EXPECT_EQ(r[0]["c"].val(), "d");
+}
+
+TEST(set_root_as_stream, root_is_docmap)
+{
+    Tree t = parse_in_arena(R"({a: b, c: d})");
+    t._p(t.root_id())->m_type.add(DOC);
+    NodeRef r = t.rootref();
+    EXPECT_EQ(r.is_stream(), false);
+    EXPECT_EQ(r.is_doc(), true);
+    EXPECT_EQ(r.is_map(), true);
+    EXPECT_EQ(r.is_seq(), false);
+    EXPECT_EQ(r.num_children(), 2u);
+    print_tree(t);
+    std::cout << t;
+    t.set_root_as_stream();
+    print_tree(t);
+    std::cout << t;
+    EXPECT_EQ(r.is_stream(), true);
+    EXPECT_EQ(r.is_doc(), false);
+    EXPECT_EQ(r.is_map(), false);
+    EXPECT_EQ(r.is_seq(), true);
+    EXPECT_EQ(r.num_children(), 1u);
+    EXPECT_EQ(r[0].is_doc(), true);
+    EXPECT_EQ(r[0].is_map(), true);
+    EXPECT_EQ(r[0].is_seq(), false);
+    EXPECT_EQ(r[0].num_children(), 2u);
+    EXPECT_EQ(r[0]["a"].is_keyval(), true);
+    EXPECT_EQ(r[0]["c"].is_keyval(), true);
+    EXPECT_EQ(r[0]["a"].val(), "b");
+    EXPECT_EQ(r[0]["c"].val(), "d");
+}
+
+
+TEST(set_root_as_stream, root_is_seq)
+{
+    Tree t = parse_in_arena(R"([a, b, c, d])");
+    NodeRef r = t.rootref();
+    EXPECT_EQ(r.is_stream(), false);
+    EXPECT_EQ(r.is_doc(), false);
+    EXPECT_EQ(r.is_map(), false);
+    EXPECT_EQ(r.is_seq(), true);
+    EXPECT_EQ(r.num_children(), 4u);
+    print_tree(t);
+    std::cout << t;
+    t.set_root_as_stream();
+    print_tree(t);
+    std::cout << t;
+    EXPECT_EQ(r.is_stream(), true);
+    EXPECT_EQ(r.is_doc(), false);
+    EXPECT_EQ(r.is_map(), false);
+    EXPECT_EQ(r.is_seq(), true);
+    EXPECT_EQ(r.num_children(), 1u);
+    EXPECT_EQ(r[0].is_doc(), true);
+    EXPECT_EQ(r[0].is_map(), false);
+    EXPECT_EQ(r[0].is_seq(), true);
+    EXPECT_EQ(r[0].num_children(), 4u);
+    EXPECT_EQ(r[0][0].val(), "a");
+    EXPECT_EQ(r[0][1].val(), "b");
+    EXPECT_EQ(r[0][2].val(), "c");
+    EXPECT_EQ(r[0][3].val(), "d");
+}
+
+TEST(set_root_as_stream, root_is_docseq)
+{
+    Tree t = parse_in_arena(R"([a, b, c, d])");
+    t._p(t.root_id())->m_type.add(DOC);
+    NodeRef r = t.rootref();
+    EXPECT_EQ(r.is_stream(), false);
+    EXPECT_EQ(r.is_doc(), true);
+    EXPECT_EQ(r.is_map(), false);
+    EXPECT_EQ(r.is_seq(), true);
+    EXPECT_EQ(r.num_children(), 4u);
+    print_tree(t);
+    std::cout << t;
+    t.set_root_as_stream();
+    print_tree(t);
+    std::cout << t;
+    EXPECT_EQ(r.is_stream(), true);
+    EXPECT_EQ(r.is_doc(), false);
+    EXPECT_EQ(r.is_map(), false);
+    EXPECT_EQ(r.is_seq(), true);
+    EXPECT_EQ(r.num_children(), 1u);
+    EXPECT_EQ(r[0].is_doc(), true);
+    EXPECT_EQ(r[0].is_map(), false);
+    EXPECT_EQ(r[0].is_seq(), true);
+    EXPECT_EQ(r[0].num_children(), 4u);
+    EXPECT_EQ(r[0][0].val(), "a");
+    EXPECT_EQ(r[0][1].val(), "b");
+    EXPECT_EQ(r[0][2].val(), "c");
+    EXPECT_EQ(r[0][3].val(), "d");
+}
+
+TEST(set_root_as_stream, root_is_seqmap)
+{
+    Tree t = parse_in_arena(R"([{a: b, c: d}, {e: e, f: f}, {g: g, h: h}, {i: i, j: j}])");
+    NodeRef r = t.rootref();
+    EXPECT_EQ(r.is_stream(), false);
+    EXPECT_EQ(r.is_doc(), false);
+    EXPECT_EQ(r.is_map(), false);
+    EXPECT_EQ(r.is_seq(), true);
+    EXPECT_EQ(r.num_children(), 4u);
+    print_tree(t);
+    std::cout << t;
+    t.set_root_as_stream();
+    print_tree(t);
+    std::cout << t;
+    EXPECT_EQ(r.is_stream(), true);
+    EXPECT_EQ(r.is_doc(), false);
+    EXPECT_EQ(r.is_map(), false);
+    EXPECT_EQ(r.is_seq(), true);
+    EXPECT_EQ(r.num_children(), 1u);
+    EXPECT_EQ(r[0].is_doc(), true);
+    EXPECT_EQ(r[0].is_map(), false);
+    EXPECT_EQ(r[0].is_seq(), true);
+    EXPECT_EQ(r[0].num_children(), 4u);
+    EXPECT_EQ(r[0][0].is_map(), true);
+    EXPECT_EQ(r[0][1].is_map(), true);
+    EXPECT_EQ(r[0][2].is_map(), true);
+    EXPECT_EQ(r[0][3].is_map(), true);
+    EXPECT_EQ(r[0][0]["a"].val(), "b");
+    EXPECT_EQ(r[0][0]["c"].val(), "d");
+    EXPECT_EQ(r[0][1]["e"].val(), "e");
+    EXPECT_EQ(r[0][1]["f"].val(), "f");
+    EXPECT_EQ(r[0][2]["g"].val(), "g");
+    EXPECT_EQ(r[0][2]["h"].val(), "h");
+    EXPECT_EQ(r[0][3]["i"].val(), "i");
+    EXPECT_EQ(r[0][3]["j"].val(), "j");
+}
+
+TEST(set_root_as_stream, root_is_mapseq)
+{
+    Tree t = parse_in_arena(R"({a: [0, 1, 2], b: [3, 4, 5], c: [6, 7, 8]})");
+    NodeRef r = t.rootref();
+    EXPECT_EQ(r.is_stream(), false);
+    EXPECT_EQ(r.is_doc(), false);
+    EXPECT_EQ(r.is_map(), true);
+    EXPECT_EQ(r.is_seq(), false);
+    EXPECT_EQ(r.num_children(), 3u);
+    print_tree(t);
+    std::cout << t;
+    t.set_root_as_stream();
+    print_tree(t);
+    std::cout << t;
+    EXPECT_EQ(r.is_stream(), true);
+    EXPECT_EQ(r.is_doc(), false);
+    EXPECT_EQ(r.is_map(), false);
+    EXPECT_EQ(r.is_seq(), true);
+    EXPECT_EQ(r.num_children(), 1u);
+    EXPECT_EQ(r[0].is_doc(), true);
+    EXPECT_EQ(r[0].is_map(), true);
+    EXPECT_EQ(r[0].is_seq(), false);
+    EXPECT_EQ(r[0].num_children(), 3u);
+    EXPECT_EQ(r[0]["a"].is_seq(), true);
+    EXPECT_EQ(r[0]["b"].is_seq(), true);
+    EXPECT_EQ(r[0]["c"].is_seq(), true);
+    EXPECT_EQ(r[0]["a"][0].val(), "0");
+    EXPECT_EQ(r[0]["a"][1].val(), "1");
+    EXPECT_EQ(r[0]["a"][2].val(), "2");
+    EXPECT_EQ(r[0]["b"][0].val(), "3");
+    EXPECT_EQ(r[0]["b"][1].val(), "4");
+    EXPECT_EQ(r[0]["b"][2].val(), "5");
+    EXPECT_EQ(r[0]["c"][0].val(), "6");
+    EXPECT_EQ(r[0]["c"][1].val(), "7");
+    EXPECT_EQ(r[0]["c"][2].val(), "8");
+}
+
+TEST(set_root_as_stream, root_is_docval)
+{
+    Tree t;
+    NodeRef r = t.rootref();
+    r.set_type(DOCVAL);
+    r.set_val("bar");
+    r.set_val_tag("<!foo>");
+    EXPECT_EQ(r.is_stream(), false);
+    EXPECT_EQ(r.is_doc(), true);
+    EXPECT_EQ(r.is_map(), false);
+    EXPECT_EQ(r.is_seq(), false);
+    EXPECT_EQ(r.is_val(), true);
+    EXPECT_EQ(r.has_val_tag(), true);
+    EXPECT_EQ(r.val_tag(), "<!foo>");
+    EXPECT_EQ(r.num_children(), 0u);
+    print_tree(t);
+    std::cout << t;
+    t.set_root_as_stream();
+    print_tree(t);
+    std::cout << t;
+    EXPECT_EQ(r.is_stream(), true);
+    EXPECT_EQ(r.is_doc(), false);
+    EXPECT_EQ(r.is_map(), false);
+    EXPECT_EQ(r.is_seq(), true);
+    EXPECT_EQ(r.is_val(), false);
+    ASSERT_EQ(r.num_children(), 1u);
+    EXPECT_EQ(r[0].is_stream(), false);
+    EXPECT_EQ(r[0].is_doc(), true);
+    EXPECT_EQ(r[0].is_map(), false);
+    EXPECT_EQ(r[0].is_seq(), false);
+    EXPECT_EQ(r[0].is_val(), true);
+    EXPECT_EQ(r[0].has_val_tag(), true);
+    EXPECT_EQ(r[0].val_tag(), "<!foo>");
+    EXPECT_EQ(r[0].num_children(), 0u);
+}
+
+
+//-------------------------------------------
+//-------------------------------------------
+//-------------------------------------------
+
+TEST(Tree, doc)
+{
+    Tree t = parse_in_arena(R"(---
+doc0
+---
+doc1
+---
+doc2
+---
+doc3
+---
+doc4
+)");
+    size_t ir = t.root_id();
+    ASSERT_EQ(t.num_children(ir), 5u);
+    ASSERT_TRUE(t.is_stream(ir));
+    EXPECT_EQ(t.child(ir, 0), t.doc(0));
+    EXPECT_EQ(t.child(ir, 1), t.doc(1));
+    EXPECT_EQ(t.child(ir, 2), t.doc(2));
+    EXPECT_EQ(t.child(ir, 3), t.doc(3));
+    EXPECT_EQ(t.child(ir, 4), t.doc(4));
+    {
+        NodeRef r = t.rootref();
+        EXPECT_EQ(r.id(), ir);
+        EXPECT_EQ(r.child(0), r.doc(0));
+        EXPECT_EQ(r.child(1), r.doc(1));
+        EXPECT_EQ(r.child(2), r.doc(2));
+        EXPECT_EQ(r.child(3), r.doc(3));
+        EXPECT_EQ(r.child(4), r.doc(4));
+        EXPECT_EQ(r.child(0).id(), t.doc(0));
+        EXPECT_EQ(r.child(1).id(), t.doc(1));
+        EXPECT_EQ(r.child(2).id(), t.doc(2));
+        EXPECT_EQ(r.child(3).id(), t.doc(3));
+        EXPECT_EQ(r.child(4).id(), t.doc(4));
+        EXPECT_EQ(r.child(0).id(), t.docref(0).id());
+        EXPECT_EQ(r.child(1).id(), t.docref(1).id());
+        EXPECT_EQ(r.child(2).id(), t.docref(2).id());
+        EXPECT_EQ(r.child(3).id(), t.docref(3).id());
+        EXPECT_EQ(r.child(4).id(), t.docref(4).id());
+    }
+    {
+        const Tree &ct = t;
+        const ConstNodeRef r = ct.rootref();
+        EXPECT_EQ(r.id(), ir);
+        EXPECT_EQ(r.child(0), r.doc(0));
+        EXPECT_EQ(r.child(1), r.doc(1));
+        EXPECT_EQ(r.child(2), r.doc(2));
+        EXPECT_EQ(r.child(3), r.doc(3));
+        EXPECT_EQ(r.child(4), r.doc(4));
+        EXPECT_EQ(r.child(0).id(), t.doc(0));
+        EXPECT_EQ(r.child(1).id(), t.doc(1));
+        EXPECT_EQ(r.child(2).id(), t.doc(2));
+        EXPECT_EQ(r.child(3).id(), t.doc(3));
+        EXPECT_EQ(r.child(4).id(), t.doc(4));
+        EXPECT_EQ(r.child(0).id(), t.docref(0).id());
+        EXPECT_EQ(r.child(1).id(), t.docref(1).id());
+        EXPECT_EQ(r.child(2).id(), t.docref(2).id());
+        EXPECT_EQ(r.child(3).id(), t.docref(3).id());
+        EXPECT_EQ(r.child(4).id(), t.docref(4).id());
+    }
+}
+
+
+//-------------------------------------------
+//-------------------------------------------
+//-------------------------------------------
+
+TEST(Tree, add_tag_directives)
+{
+    #if RYML_MAX_TAG_DIRECTIVES != 4
+    #error this test assumes RYML_MAX_TAG_DIRECTIVES == 4
+    #endif
+    const TagDirective td[RYML_MAX_TAG_DIRECTIVES + 1] = {
+        TagDirective{csubstr("!a!"), csubstr("!ay-"), 0u},
+        TagDirective{csubstr("!b!"), csubstr("!by-"), 0u},
+        TagDirective{csubstr("!c!"), csubstr("!cy-"), 0u},
+        TagDirective{csubstr("!d!"), csubstr("!dy-"), 0u},
+        TagDirective{csubstr("!e!"), csubstr("!ey-"), 0u},
+    };
+    Tree t;
+    auto check_up_to = [&](size_t num)
+    {
+        size_t pos = 0;
+        EXPECT_EQ(t.num_tag_directives(), num);
+        for(TagDirective const& d : t.tag_directives())
+        {
+            EXPECT_EQ(d.handle.str, td[pos].handle.str);
+            EXPECT_EQ(d.handle.len, td[pos].handle.len);
+            EXPECT_EQ(d.prefix.str, td[pos].prefix.str);
+            EXPECT_EQ(d.prefix.str, td[pos].prefix.str);
+            EXPECT_EQ(d.next_node_id, td[pos].next_node_id);
+            ++pos;
+        }
+        EXPECT_EQ(pos, num);
+    };
+    check_up_to(0);
+    t.add_tag_directive(td[0]);
+    check_up_to(1);
+    t.add_tag_directive(td[1]);
+    check_up_to(2);
+    t.add_tag_directive(td[2]);
+    check_up_to(3);
+    t.add_tag_directive(td[3]);
+    check_up_to(4);
+    ExpectError::do_check(&t, [&]{ // number exceeded
+        t.add_tag_directive(td[4]);
+    });
+    t.clear_tag_directives();
+    check_up_to(0);
+}
+
+TEST(Tree, resolve_tag)
+{
+    csubstr yaml = R"(
+#%TAG !m! !my-
+--- # Bulb here
+!m!light fluorescent
+...
+#%TAG !m! !meta-
+--- # Color here
+!m!light green
+)";
+    // we're not testing the parser here, just the tag mechanics.
+    // So we'll add the tag directives by hand.
+    Tree t = parse_in_arena(yaml);
+    EXPECT_EQ(t[0].val_tag(), "!m!light");
+    EXPECT_EQ(t[1].val_tag(), "!m!light");
+    EXPECT_EQ(t.num_tag_directives(), 0u);
+    t.add_tag_directive(TagDirective{csubstr("!m!"), csubstr("!my-"), 1});
+    t.add_tag_directive(TagDirective{csubstr("!m!"), csubstr("!meta-"), 2});
+    EXPECT_EQ(t.num_tag_directives(), 2u);
+    char buf_[100];
+    EXPECT_EQ(t.resolve_tag_sub(buf_, "!m!light", 1u), csubstr("<!my-light>"));
+    EXPECT_EQ(t.resolve_tag_sub(buf_, "!m!light", 2u), csubstr("<!meta-light>"));
+}
+
+
+//-------------------------------------------
+// this is needed to use the test case library
+Case const* get_case(csubstr /*name*/)
+{
+    return nullptr;
+}
+
+} // namespace yml
+} // namespace c4
+
+#if defined(_MSC_VER)
+#   pragma warning(pop)
+#elif defined(__clang__)
+#   pragma clang diagnostic pop
+#elif defined(__GNUC__)
+#   pragma GCC diagnostic pop
+#endif