fix syntax

Author: vendethiel

lib/ast.js

@@ -2817,6 +2817,9 @@ exports.For = For = (function(superclass){
       o.ref = this.item.value;
     }
     if (this['let']) {
+      if (that = this.body.getJump()) {
+        that instanceof Return || that.carp('inconvertible statement');
+      }
       if (this.returns) {
         this.body = this.body.makeReturn();
       }

lib/lexer.js

@@ -136,6 +136,9 @@ exports.doID = function(code, index){
   case 'super':
     return this.token('LITERAL', id, true).length;
   case 'for':
+    if ((ref$ = this.tokens)[ref$.length - 1][0] === 'LET') {
+      this.carp("unexpected 'FOR'");
+    }
     this.seenFor = true;
     this.wantBy = false;
     break;
@@ -206,9 +209,11 @@ exports.doID = function(code, index){
     break;
   case 'let':
     if ((ref$ = this.tokens)[ref$.length - 1][0] === 'FOR') {
-      this.tokens.pop();
-      this.token('LET', 'let');
-      this.token('FOR', 'for');
+      this.tokens.splice(this.tokens.length - 1, 0, ['LET', 'let']);
+      return input.length;
+    }
+    if ((ref$ = this.tokens)[ref$.length - 1][0] === 'OWN' && (ref$ = this.tokens)[ref$.length - 2][0] === 'FOR') {
+      this.tokens.splice(this.tokens.length - 2, 0, ['LET', 'let']);
       return input.length;
     }
     break;

src/ast.co

@@ -1746,6 +1746,8 @@ class exports.For extends While
         head += \\n + o.indent + itemAssign.compile(o, LEVEL_TOP) + \;
     o.ref = @item.value if @ref
     if @let
+      if @body.getJump!
+        that instanceof Return or that.carp 'inconvertible statement'
       @body.=makeReturn! if @returns
       @body = Block Call.let capture, @body
     body  = @compileBody o

src/lexer.co

@@ -105,7 +105,10 @@ exports import
     case \return \throw                                then tag = \HURL
     case \break  \continue                             then tag = \JUMP
     case \this \eval \super then return @token(\LITERAL id, true)length
-    case \for  then @seenFor = true; @wantBy = false
+    case \for  then
+      if @tokens[*-1]0 is \LET
+        @carp "unexpected 'FOR'"
+      @seenFor = true; @wantBy = false
     case \then then @seenFor = @wantBy = false
     case \catch \function then id = ''
     case \in \of
@@ -139,11 +142,13 @@ exports import
       if able @tokens then id = \<<<; break
       fallthrough
     case \export \const \var then tag = \DECL
-    case \let then if @tokens[*-1]0 is \FOR
-      @tokens.pop!
-      @token \LET \let
-      @token \FOR \for
-      return input.length
+    case \let then
+      if @tokens[*-1]0 is \FOR
+        @tokens.splice @tokens.length-1 0 <[LET let]>
+        return input.length
+      if @tokens[*-1]0 is \OWN and @tokens[*-2]0 is \FOR
+        @tokens.splice @tokens.length-2 0 <[LET let]>
+        return input.length
     default
       break if id of KEYWORDS_SHARED
       @carp "reserved word \"#id\"" if id of KEYWORDS_UNUSED

test/loop.co

@@ -342,6 +342,24 @@ for [0]
   for [2] =>   ok 2 of [2]
   ok 3 not in []
 
+# `(1; continue)` to avoid `continue` getting optimized away by `While::addBody`
+compileThrows 'inconvertible statement' 1 'for let a in b then (1; continue)'
+compileThrows 'inconvertible statement' 1 'for let a in b then break'
+compileThrows "unexpected 'FOR'" 1 'let for a in b then'
+
+# parses correctly with `own`
+for own let a in []
+  1
+
+for let own a in []
+  1
+
+i = 2
+a = while --i
+  for let a of [0 1]
+    a + i
+ok '' ''+a
+
 x = 2
 for let a in []
   x = 3