Move all non-decl/non-expr stmts to exprs.

6 files changed, 212 insertions, 193 deletions

diff --git a/src/comp/front/ast.rs b/src/comp/front/ast.rs
index 820bbbfa..53ffdd87 100644
--- a/src/comp/front/ast.rs
+++ b/src/comp/front/ast.rs
@@ -116,11 +116,6 @@ tag mode {
 type stmt = spanned[stmt_];
 tag stmt_ {
     stmt_decl(@decl);
-    stmt_ret(option.t[@expr]);
-    stmt_be(@expr);
-    stmt_log(@expr);
-    stmt_check_expr(@expr);
-    stmt_fail;
     stmt_expr(@expr);
 }
 
@@ -165,6 +160,11 @@ tag expr_ {
     expr_index(@expr, @expr, ann);
     expr_path(path, option.t[def], ann);
     expr_ext(vec[@expr], option.t[@expr], ann);
+    expr_fail;
+    expr_ret(option.t[@expr]);
+    expr_be(@expr);
+    expr_log(@expr);
+    expr_check_expr(@expr);
 }
 
 type lit = spanned[lit_];
diff --git a/src/comp/front/parser.rs b/src/comp/front/parser.rs
index 1296113a..5ffaca19 100644
--- a/src/comp/front/parser.rs
+++ b/src/comp/front/parser.rs
@@ -598,6 +598,59 @@ impure fn parse_bottom_expr(parser p) -> @ast.expr {
             ex = ast.expr_ext(es.node, none[@ast.expr], ast.ann_none);
         }
 
+        case (token.FAIL) {
+            p.bump();
+            ex = ast.expr_fail;
+        }
+
+        case (token.LOG) {
+            p.bump();
+            auto e = parse_expr(p);
+            auto hi = e.span;
+            ex = ast.expr_log(e);
+        }
+
+        case (token.CHECK) {
+            p.bump();
+            alt (p.peek()) {
+                case (token.LPAREN) {
+                    auto e = parse_expr(p);
+                    auto hi = e.span;
+                    ex = ast.expr_check_expr(e);
+                }
+                case (_) {
+                    p.get_session().unimpl("constraint-check stmt");
+                }
+            }
+        }
+
+        case (token.RET) {
+            p.bump();
+            alt (p.peek()) {
+                case (token.SEMI) {
+                    ex = ast.expr_ret(none[@ast.expr]);
+                }
+                case (_) {
+                    auto e = parse_expr(p);
+                    hi = e.span;
+                    ex = ast.expr_ret(some[@ast.expr](e));
+                }
+            }
+        }
+
+        case (token.BE) {
+            p.bump();
+            auto e = parse_expr(p);
+            // FIXME: Is this the right place for this check?
+            if /*check*/ (ast.is_call_expr(e)) {
+                    hi = e.span;
+                    ex = ast.expr_be(e);
+            }
+            else {
+                p.err("Non-call expression in tail call");
+            }
+        }
+
         case (_) {
             auto lit = parse_lit(p);
             hi = lit.span;
@@ -1203,59 +1256,6 @@ impure fn parse_stmt(parser p) -> @ast.stmt {
     auto lo = p.get_span();
     alt (p.peek()) {
 
-        case (token.LOG) {
-            p.bump();
-            auto e = parse_expr(p);
-            auto hi = p.get_span();
-            ret @spanned(lo, hi, ast.stmt_log(e));
-        }
-
-        case (token.CHECK) {
-            p.bump();
-            alt (p.peek()) {
-                case (token.LPAREN) {
-                    auto e = parse_expr(p);
-                    auto hi = p.get_span();
-                    ret @spanned(lo, hi, ast.stmt_check_expr(e));
-                }
-                case (_) {
-                    p.get_session().unimpl("constraint-check stmt");
-                }
-            }
-        }
-
-        case (token.FAIL) {
-            p.bump();
-            ret @spanned(lo, p.get_span(), ast.stmt_fail);
-        }
-
-        case (token.RET) {
-            p.bump();
-            alt (p.peek()) {
-                case (token.SEMI) {
-                    ret @spanned(lo, p.get_span(),
-                                 ast.stmt_ret(none[@ast.expr]));
-                }
-                case (_) {
-                    auto e = parse_expr(p);
-                    ret @spanned(lo, e.span,
-                                 ast.stmt_ret(some[@ast.expr](e)));
-                }
-            }
-        }
-
-        case (token.BE) {
-            p.bump();
-            auto e = parse_expr(p);
-            // FIXME: Is this the right place for this check?
-            if /*check*/ (ast.is_call_expr(e)) {
-                ret @spanned(lo, e.span, ast.stmt_be(e));
-            }
-            else {
-                p.err("Non-call expression in tail call");
-            }
-        }
-
         case (token.LET) {
             auto decl = parse_let(p);
             auto hi = p.get_span();
@@ -1396,11 +1396,6 @@ fn stmt_ends_with_semi(@ast.stmt stmt) -> bool {
                 case (ast.decl_item(_)) { ret false; }
             }
         }
-        case (ast.stmt_ret(_))                  { ret true; }
-        case (ast.stmt_be(_))                   { ret true; }
-        case (ast.stmt_log(_))                  { ret true; }
-        case (ast.stmt_check_expr(_))           { ret true; }
-        case (ast.stmt_fail)                    { ret true; }
         case (ast.stmt_expr(?e)) {
             alt (e.node) {
                 case (ast.expr_vec(_,_))        { ret true; }
@@ -1423,6 +1418,11 @@ fn stmt_ends_with_semi(@ast.stmt stmt) -> bool {
                 case (ast.expr_field(_,_,_))    { ret true; }
                 case (ast.expr_index(_,_,_))    { ret true; }
                 case (ast.expr_path(_,_,_))     { ret true; }
+                case (ast.expr_fail)            { ret true; }
+                case (ast.expr_ret(_))          { ret true; }
+                case (ast.expr_be(_))           { ret true; }
+                case (ast.expr_log(_))          { ret true; }
+                case (ast.expr_check_expr(_))   { ret true; }
             }
         }
     }
diff --git a/src/comp/middle/fold.rs b/src/comp/middle/fold.rs
index 4ba65a7b..4e8ea317 100644
--- a/src/comp/middle/fold.rs
+++ b/src/comp/middle/fold.rs
@@ -149,6 +149,20 @@ type ast_fold[ENV] =
          &option.t[def] d,
          ann a) -> @expr)                         fold_expr_path,
 
+     (fn(&ENV e, &span sp) -> @expr)              fold_expr_fail,
+
+     (fn(&ENV e, &span sp,
+         &option.t[@expr] rv) -> @expr)           fold_expr_ret,
+
+     (fn(&ENV e, &span sp,
+         @expr e) -> @expr)                       fold_expr_be,
+
+     (fn(&ENV e, &span sp,
+         @expr e) -> @expr)                       fold_expr_log,
+
+     (fn(&ENV e, &span sp,
+         @expr e) -> @expr)                       fold_expr_check_expr,
+
      // Decl folds.
      (fn(&ENV e, &span sp,
          @ast.local local) -> @decl)              fold_decl_local,
@@ -178,18 +192,6 @@ type ast_fold[ENV] =
          @decl decl) -> @stmt)                    fold_stmt_decl,
 
      (fn(&ENV e, &span sp,
-         &option.t[@expr] rv) -> @stmt)           fold_stmt_ret,
-
-     (fn(&ENV e, &span sp,
-         @expr e) -> @stmt)                       fold_stmt_be,
-
-     (fn(&ENV e, &span sp,
-         @expr e) -> @stmt)                       fold_stmt_log,
-
-     (fn(&ENV e, &span sp,
-         @expr e) -> @stmt)                       fold_stmt_check_expr,
-
-     (fn(&ENV e, &span sp,
          @expr e) -> @stmt)                       fold_stmt_expr,
 
      // Item folds.
@@ -622,6 +624,37 @@ fn fold_expr[ENV](&ENV env, ast_fold[ENV] fld, &@expr e) -> @expr {
             auto p_ = fold_path(env_, fld, p);
             ret fld.fold_expr_path(env_, e.span, p_, r, t);
         }
+
+        case (ast.expr_fail) {
+            ret fld.fold_expr_fail(env_, e.span);
+        }
+
+        case (ast.expr_ret(?oe)) {
+            auto oee = none[@expr];
+            alt (oe) {
+                case (some[@expr](?x)) {
+                    oee = some(fold_expr(env_, fld, x));
+                }
+                case (_) { /* fall through */  }
+            }
+            ret fld.fold_expr_ret(env_, e.span, oee);
+        }
+
+        case (ast.expr_be(?x)) {
+            auto ee = fold_expr(env_, fld, x);
+            ret fld.fold_expr_be(env_, e.span, ee);
+        }
+
+        case (ast.expr_log(?x)) {
+            auto ee = fold_expr(env_, fld, x);
+            ret fld.fold_expr_log(env_, e.span, ee);
+        }
+
+        case (ast.expr_check_expr(?x)) {
+            auto ee = fold_expr(env_, fld, x);
+            ret fld.fold_expr_check_expr(env_, e.span, ee);
+        }
+
     }
 
     ret e;
@@ -642,36 +675,6 @@ fn fold_stmt[ENV](&ENV env, ast_fold[ENV] fld, &@stmt s) -> @stmt {
             ret fld.fold_stmt_decl(env_, s.span, dd);
         }
 
-        case (ast.stmt_ret(?oe)) {
-            auto oee = none[@expr];
-            alt (oe) {
-                case (some[@expr](?e)) {
-                    oee = some(fold_expr(env_, fld, e));
-                }
-                case (_) { /* fall through */  }
-            }
-            ret fld.fold_stmt_ret(env_, s.span, oee);
-        }
-
-        case (ast.stmt_be(?e)) {
-            auto ee = fold_expr(env_, fld, e);
-            ret fld.fold_stmt_be(env_, s.span, ee);
-        }
-
-        case (ast.stmt_log(?e)) {
-            auto ee = fold_expr(env_, fld, e);
-            ret fld.fold_stmt_log(env_, s.span, ee);
-        }
-
-        case (ast.stmt_check_expr(?e)) {
-            auto ee = fold_expr(env_, fld, e);
-            ret fld.fold_stmt_check_expr(env_, s.span, ee);
-        }
-
-        case (ast.stmt_fail) {
-            ret s;
-        }
-
         case (ast.stmt_expr(?e)) {
             auto ee = fold_expr(env_, fld, e);
             ret fld.fold_stmt_expr(env_, s.span, ee);
@@ -1118,6 +1121,27 @@ fn identity_fold_expr_path[ENV](&ENV env, &span sp,
     ret @respan(sp, ast.expr_path(p, d, a));
 }
 
+fn identity_fold_expr_fail[ENV](&ENV env, &span sp) -> @expr {
+    ret @respan(sp, ast.expr_fail);
+}
+
+fn identity_fold_expr_ret[ENV](&ENV env, &span sp,
+                               &option.t[@expr] rv) -> @expr {
+    ret @respan(sp, ast.expr_ret(rv));
+}
+
+fn identity_fold_expr_be[ENV](&ENV env, &span sp, @expr x) -> @expr {
+    ret @respan(sp, ast.expr_be(x));
+}
+
+fn identity_fold_expr_log[ENV](&ENV e, &span sp, @expr x) -> @expr {
+    ret @respan(sp, ast.expr_log(x));
+}
+
+fn identity_fold_expr_check_expr[ENV](&ENV e, &span sp, @expr x) -> @expr {
+    ret @respan(sp, ast.expr_check_expr(x));
+}
+
 
 // Decl identities.
 
@@ -1158,23 +1182,6 @@ fn identity_fold_stmt_decl[ENV](&ENV env, &span sp, @decl d) -> @stmt {
     ret @respan(sp, ast.stmt_decl(d));
 }
 
-fn identity_fold_stmt_ret[ENV](&ENV env, &span sp,
-                               &option.t[@expr] rv) -> @stmt {
-    ret @respan(sp, ast.stmt_ret(rv));
-}
-
-fn identity_fold_stmt_be[ENV](&ENV env, &span sp, @expr x) -> @stmt {
-    ret @respan(sp, ast.stmt_be(x));
-}
-
-fn identity_fold_stmt_log[ENV](&ENV e, &span sp, @expr x) -> @stmt {
-    ret @respan(sp, ast.stmt_log(x));
-}
-
-fn identity_fold_stmt_check_expr[ENV](&ENV e, &span sp, @expr x) -> @stmt {
-    ret @respan(sp, ast.stmt_check_expr(x));
-}
-
 fn identity_fold_stmt_expr[ENV](&ENV e, &span sp, @expr x) -> @stmt {
     ret @respan(sp, ast.stmt_expr(x));
 }
@@ -1387,6 +1394,12 @@ fn new_identity_fold[ENV]() -> ast_fold[ENV] {
          fold_expr_field  = bind identity_fold_expr_field[ENV](_,_,_,_,_),
          fold_expr_index  = bind identity_fold_expr_index[ENV](_,_,_,_,_),
          fold_expr_path   = bind identity_fold_expr_path[ENV](_,_,_,_,_),
+         fold_expr_fail   = bind identity_fold_expr_fail[ENV](_,_),
+         fold_expr_ret    = bind identity_fold_expr_ret[ENV](_,_,_),
+         fold_expr_be     = bind identity_fold_expr_be[ENV](_,_,_),
+         fold_expr_log    = bind identity_fold_expr_log[ENV](_,_,_),
+         fold_expr_check_expr
+                          = bind identity_fold_expr_check_expr[ENV](_,_,_),
 
          fold_decl_local  = bind identity_fold_decl_local[ENV](_,_,_),
          fold_decl_item   = bind identity_fold_decl_item[ENV](_,_,_),
@@ -1397,11 +1410,6 @@ fn new_identity_fold[ENV]() -> ast_fold[ENV] {
          fold_pat_tag     = bind identity_fold_pat_tag[ENV](_,_,_,_,_,_),
 
          fold_stmt_decl   = bind identity_fold_stmt_decl[ENV](_,_,_),
-         fold_stmt_ret    = bind identity_fold_stmt_ret[ENV](_,_,_),
-         fold_stmt_be     = bind identity_fold_stmt_be[ENV](_,_,_),
-         fold_stmt_log    = bind identity_fold_stmt_log[ENV](_,_,_),
-         fold_stmt_check_expr
-                          = bind identity_fold_stmt_check_expr[ENV](_,_,_),
          fold_stmt_expr   = bind identity_fold_stmt_expr[ENV](_,_,_),
 
          fold_item_const= bind identity_fold_item_const[ENV](_,_,_,_,_,_,_),
diff --git a/src/comp/middle/trans.rs b/src/comp/middle/trans.rs
index 1bf278a7..e140ddcc 100644
--- a/src/comp/middle/trans.rs
+++ b/src/comp/middle/trans.rs
@@ -3106,6 +3106,26 @@ fn trans_expr(@block_ctxt cx, @ast.expr e) -> result {
             ret trans_rec(cx, args, base, ann);
         }
 
+        case (ast.expr_fail) {
+            ret trans_fail(cx, e.span, "explicit failure");
+        }
+
+        case (ast.expr_log(?a)) {
+            ret trans_log(cx, a);
+        }
+
+        case (ast.expr_check_expr(?a)) {
+            ret trans_check_expr(cx, a);
+        }
+
+        case (ast.expr_ret(?e)) {
+            ret trans_ret(cx, e);
+        }
+
+        case (ast.expr_be(?e)) {
+            ret trans_be(cx, e);
+        }
+
         // lval cases fall through to trans_lval and then
         // possibly load the result (if it's non-structural).
 
@@ -3255,26 +3275,6 @@ fn init_local(@block_ctxt cx, @ast.local local) -> result {
 fn trans_stmt(@block_ctxt cx, &ast.stmt s) -> result {
     auto bcx = cx;
     alt (s.node) {
-        case (ast.stmt_log(?a)) {
-            bcx = trans_log(cx, a).bcx;
-        }
-
-        case (ast.stmt_check_expr(?a)) {
-            bcx = trans_check_expr(cx, a).bcx;
-        }
-
-        case (ast.stmt_fail) {
-            bcx = trans_fail(cx, s.span, "explicit failure").bcx;
-        }
-
-        case (ast.stmt_ret(?e)) {
-            bcx = trans_ret(cx, e).bcx;
-        }
-
-        case (ast.stmt_be(?e)) {
-            bcx = trans_be(cx, e).bcx;
-        }
-
         case (ast.stmt_expr(?e)) {
             bcx = trans_expr(cx, e).bcx;
         }
diff --git a/src/comp/middle/ty.rs b/src/comp/middle/ty.rs
index 2083ef2b..58529d0d 100644
--- a/src/comp/middle/ty.rs
+++ b/src/comp/middle/ty.rs
@@ -686,6 +686,12 @@ fn expr_ty(@ast.expr expr) -> @t {
         case (ast.expr_field(_, _, ?ann))     { ret ann_to_type(ann); }
         case (ast.expr_index(_, _, ?ann))     { ret ann_to_type(ann); }
         case (ast.expr_path(_, _, ?ann))      { ret ann_to_type(ann); }
+
+        case (ast.expr_fail)                  { ret plain_ty(ty_nil); }
+        case (ast.expr_log(_))                { ret plain_ty(ty_nil); }
+        case (ast.expr_check_expr(_))         { ret plain_ty(ty_nil); }
+        case (ast.expr_ret(_))                { ret plain_ty(ty_nil); }
+        case (ast.expr_be(_))                 { ret plain_ty(ty_nil); }
     }
     fail;
 }
diff --git a/src/comp/middle/typeck.rs b/src/comp/middle/typeck.rs
index 19e4a9b2..d0043c43 100644
--- a/src/comp/middle/typeck.rs
+++ b/src/comp/middle/typeck.rs
@@ -1037,6 +1037,11 @@ fn demand_expr_full(&@fn_ctxt fcx, @ty.t expected, @ast.expr e,
                                  ann_to_type(ann), adk);
             e_1 = ast.expr_path(pth, d, ast.ann_type(t));
         }
+        case (ast.expr_fail) { e_1 = e.node; }
+        case (ast.expr_log(_)) { e_1 = e.node; }
+        case (ast.expr_ret(_)) { e_1 = e.node; }
+        case (ast.expr_be(_)) { e_1 = e.node; }
+        case (ast.expr_check_expr(_)) { e_1 = e.node; }
     }
 
     ret @fold.respan[ast.expr_](e.span, e_1);
@@ -1287,6 +1292,52 @@ fn check_expr(&@fn_ctxt fcx, @ast.expr expr) -> @ast.expr {
                                                       ast.ann_type(t)));
         }
 
+        case (ast.expr_fail) {
+            ret expr;
+        }
+
+        case (ast.expr_ret(?expr_opt)) {
+            alt (expr_opt) {
+                case (none[@ast.expr]) {
+                    auto nil = plain_ty(ty.ty_nil);
+                    if (!are_compatible(fcx, fcx.ret_ty, nil)) {
+                        fcx.ccx.sess.err("ret; in function "
+                                         + "returning non-nil");
+                    }
+
+                    ret expr;
+                }
+
+                case (some[@ast.expr](?e)) {
+                    auto expr_0 = check_expr(fcx, e);
+                    auto expr_1 = demand_expr(fcx, fcx.ret_ty, expr_0);
+                    ret @fold.respan[ast.expr_](expr.span,
+                                                ast.expr_ret(some(expr_1)));
+                }
+            }
+        }
+
+        case (ast.expr_be(?e)) {
+            /* FIXME: prove instead of check */
+            check ast.is_call_expr(e);
+            auto expr_0 = check_expr(fcx, e);
+            auto expr_1 = demand_expr(fcx, fcx.ret_ty, expr_0);
+            ret @fold.respan[ast.expr_](expr.span,
+                                        ast.expr_be(expr_1));
+        }
+
+        case (ast.expr_log(?e)) {
+            auto expr_t = check_expr(fcx, e);
+            ret @fold.respan[ast.expr_](expr.span, ast.expr_log(expr_t));
+        }
+
+        case (ast.expr_check_expr(?e)) {
+            auto expr_t = check_expr(fcx, e);
+            demand(fcx, expr.span, plain_ty(ty.ty_bool), expr_ty(expr_t));
+            ret @fold.respan[ast.expr_](expr.span,
+                                        ast.expr_check_expr(expr_t));
+        }
+
         case (ast.expr_assign(?lhs, ?rhs, _)) {
             auto lhs_0 = check_expr(fcx, lhs);
             auto rhs_0 = check_expr(fcx, rhs);
@@ -1806,52 +1857,6 @@ fn check_stmt(&@fn_ctxt fcx, &@ast.stmt stmt) -> @ast.stmt {
             ret stmt;
         }
 
-        case (ast.stmt_ret(?expr_opt)) {
-            alt (expr_opt) {
-                case (none[@ast.expr]) {
-                    auto nil = plain_ty(ty.ty_nil);
-                    if (!are_compatible(fcx, fcx.ret_ty, nil)) {
-                        fcx.ccx.sess.err("ret; in function "
-                                         + "returning non-nil");
-                    }
-
-                    ret stmt;
-                }
-
-                case (some[@ast.expr](?expr)) {
-                    auto expr_0 = check_expr(fcx, expr);
-                    auto expr_1 = demand_expr(fcx, fcx.ret_ty, expr_0);
-                    ret @fold.respan[ast.stmt_](stmt.span,
-                                                ast.stmt_ret(some(expr_1)));
-                }
-            }
-        }
-
-        case (ast.stmt_be(?expr)) {
-            /* FIXME: prove instead of check */
-            check ast.is_call_expr(expr);
-            auto expr_0 = check_expr(fcx, expr);
-            auto expr_1 = demand_expr(fcx, fcx.ret_ty, expr_0);
-            ret @fold.respan[ast.stmt_](stmt.span,
-                                        ast.stmt_be(expr_1));
-        }
-
-        case (ast.stmt_log(?expr)) {
-            auto expr_t = check_expr(fcx, expr);
-            ret @fold.respan[ast.stmt_](stmt.span, ast.stmt_log(expr_t));
-        }
-
-        case (ast.stmt_check_expr(?expr)) {
-            auto expr_t = check_expr(fcx, expr);
-            demand(fcx, expr.span, plain_ty(ty.ty_bool), expr_ty(expr_t));
-            ret @fold.respan[ast.stmt_](stmt.span,
-                                        ast.stmt_check_expr(expr_t));
-        }
-
-        case (ast.stmt_fail) {
-            ret stmt;
-        }
-
         case (ast.stmt_expr(?expr)) {
             auto expr_t = check_expr(fcx, expr);
             ret @fold.respan[ast.stmt_](stmt.span, ast.stmt_expr(expr_t));