Merge branch 'master' into recursive-elseif

Conflicts:

	src/Makefile
	src/comp/front/ast.rs
	src/comp/front/parser.rs
	src/comp/middle/fold.rs
	src/comp/middle/trans.rs

1 files changed, 207 insertions, 0 deletions

diff --git a/src/comp/pretty/pp.rs b/src/comp/pretty/pp.rs
new file mode 100644
index 00000000..43a9220f
--- /dev/null
+++ b/src/comp/pretty/pp.rs
@@ -0,0 +1,207 @@
+import std.io;
+import std._vec;
+import std._str;
+
+tag boxtype {box_h; box_v; box_hv; box_align;}
+tag contexttype {cx_h; cx_v;}
+
+tag token {
+  brk(uint);
+  word(str);
+  cword(str); // closing token
+  open(boxtype, uint);
+  close;
+}
+
+type context = rec(contexttype tp, uint indent);
+
+type ps = @rec(mutable vec[context] context,
+               uint width,
+               mutable vec[token] buffered,
+               mutable uint scandepth,
+               mutable uint bufferedcol,
+               mutable uint col,
+               mutable bool start_of_line);
+
+fn mkstate(uint width) -> ps {
+  let vec[context] stack = vec(rec(tp=cx_v, indent=0u));
+  let vec[token] buff = vec();
+  ret @rec(mutable context=stack,
+           width=width,
+           mutable buffered=buff,
+           mutable scandepth=0u,
+           mutable bufferedcol=0u,
+           mutable col=0u,
+           mutable start_of_line=true);
+}
+
+impure fn push_context(ps p, contexttype tp, uint indent) {
+  before_print(p, false);
+  p.context = _vec.push[context](p.context, rec(tp=tp, indent=base_indent(p)
+                                                + indent));
+}
+
+impure fn pop_context(ps p) {
+  p.context = _vec.pop[context](p.context);
+}
+
+impure fn add_token(ps p, token tok) {
+  if (p.scandepth == 0u) {do_token(p, tok);}
+  else {buffer_token(p, tok);}
+}
+
+impure fn buffer_token(ps p, token tok) {
+  p.buffered += vec(tok);
+  p.bufferedcol += token_size(tok);
+  alt (p.buffered.(0)) {
+    case (brk(_)) {
+      alt (tok) {
+        case (brk(_)) {
+          if (p.scandepth == 1u) {finish_break_scan(p);}
+        }
+        case (open(box_h,_)) {p.scandepth += 1u;}
+        case (open(_,_)) {finish_break_scan(p);}
+        case (close) {
+          p.scandepth -= 1u;
+          if (p.scandepth == 0u) {finish_break_scan(p);}
+        }
+        case (_) {}
+      }
+    }
+    case (open(_,_)) {
+      if (p.bufferedcol > p.width) {finish_block_scan(p, cx_v);}
+      else {
+        alt (tok) {
+          case (open(_,_)) {p.scandepth += 1u;}
+          case (close) {
+            p.scandepth -= 1u;
+            if (p.scandepth == 0u) {finish_block_scan(p, cx_h);}
+          }
+          case (_) {}
+        }
+      }
+    }
+  }
+}
+
+impure fn finish_block_scan(ps p, contexttype tp) {
+  auto indent;
+  alt (p.buffered.(0)){
+    case (open(box_hv,?ind)) {
+      indent = ind;
+    }
+    case (open(box_align, _)) {
+      indent = p.col - base_indent(p);
+    }
+  }
+  p.scandepth = 0u;
+  push_context(p, tp, indent);
+  for (token t in _vec.shift[token](p.buffered)) {add_token(p, t);}
+}
+
+impure fn finish_break_scan(ps p) {
+  if (p.bufferedcol > p.width) {
+    write_str("\n");
+    p.col = 0u;
+  }
+  else {
+    auto width;
+    alt (p.buffered.(0)) {case(brk(?w)) {width = w;}}
+    auto i = 0u;
+    while (i < width) {write_str(" "); i+=1u;}
+    p.col += width;
+  }
+  p.scandepth = 0u;
+  for (token t in _vec.shift[token](p.buffered)) {add_token(p, t);}
+}
+
+impure fn start_scan(ps p, token tok) {
+  p.buffered = vec(tok);
+  p.scandepth = 1u;
+  p.bufferedcol = p.col;
+}
+
+fn cur_context(ps p) -> context {
+  ret p.context.(_vec.len[context](p.context)-1u);
+}
+fn base_indent(ps p) -> uint {
+  auto i = _vec.len[context](p.context);
+  while (i > 0u) {
+    i -= 1u;
+    auto cx = p.context.(i);
+    if (cx.tp == cx_v) {ret cx.indent;}
+  }
+}
+
+impure fn do_token(ps p, token tok) {
+  alt (tok) {
+    case (brk(?sz)) {
+      alt (cur_context(p).tp) {
+        case (cx_h) {
+          before_print(p, false);
+          start_scan(p, tok);
+        }
+        case (cx_v) {
+          write_str("\n");
+          p.col = 0u;
+          p.start_of_line = true;
+        }
+      }
+    }
+    case (word(?w)) {
+      before_print(p, false);
+      write_str(w);
+      p.col += _str.byte_len(w); // TODO char_len
+    }
+    case (cword(?w)) {
+      before_print(p, true);
+      write_str(w);
+      p.col += _str.byte_len(w); // TODO char_len
+    }
+    case (open(?tp, ?indent)) {
+      alt (tp) {
+        case (box_hv) {start_scan(p, tok);}
+        case (box_align) {start_scan(p, tok);}
+        case (box_h) {push_context(p, cx_h, indent);}
+        case (box_v) {push_context(p, cx_v, indent);}
+      }
+    }
+    case (close) {pop_context(p);}
+  }
+}
+
+impure fn before_print(ps p, bool closing) {
+  if (p.start_of_line) {
+    p.start_of_line = false;
+    auto ind;
+    if (closing) {ind = base_indent(p);}
+    else {ind = cur_context(p).indent;}
+    p.col = ind;
+    while (ind > 0u) {write_str(" "); ind -= 1u;}
+  }
+}
+
+fn write_str(str s) {
+  io.writefd(1, _str.bytes(s));
+}
+
+fn token_size(token tok) -> uint {
+  alt (tok) {
+    case (brk(?sz)) {ret sz;}
+    case (word(?w)) {ret _str.byte_len(w);}
+    case (cword(?w)) {ret _str.byte_len(w);}
+    case (open(_, _)) {ret 0u;} // TODO exception for V blocks?
+    case (close) {ret 0u;}
+  }
+}
+
+impure fn box(ps p, uint indent) {add_token(p, open(box_hv, indent));}
+impure fn abox(ps p) {add_token(p, open(box_align, 0u));}
+impure fn vbox(ps p, uint indent) {add_token(p, open(box_v, indent));}
+impure fn hbox(ps p, uint indent) {add_token(p, open(box_h, indent));}
+impure fn end(ps p) {add_token(p, close);}
+impure fn wrd(ps p, str wrd) {add_token(p, word(wrd));}
+impure fn cwrd(ps p, str wrd) {add_token(p, cword(wrd));}
+impure fn space(ps p) {add_token(p, brk(1u));}
+impure fn spaces(ps p, uint n) {add_token(p, brk(n));}
+impure fn line(ps p) {add_token(p, brk(0u));}