Comprehensions over break and continue

lib/nodes.js

@@ -210,7 +210,7 @@
       for (_i = 0, _len = _ref.length; _i < _len; _i++) {
         exp = _ref[_i];
         if (exp.jumps(o)) {
-          return true;
+          return exp;
         }
       }
     };
@@ -338,7 +338,11 @@
       if ((_ref = this.value) !== 'break' && _ref !== 'continue' && _ref !== 'debugger') {
         return false;
       }
-      return !(o && (o.loop || o.block && (this.value !== 'continue')));
+      if (!(o && (o.loop || o.block && (this.value !== 'continue')))) {
+        return this;
+      } else {
+        return false;
+      }
     };
     Literal.prototype.compile = function() {
       if (this.value.reserved) {
@@ -360,7 +364,7 @@
     Return.prototype.children = ['expression'];
     Return.prototype.isStatement = YES;
     Return.prototype.makeReturn = THIS;
-    Return.prototype.jumps = YES;
+    Return.prototype.jumps = THIS;
     Return.prototype.compile = function(o, level) {
       var expr, _ref;
       expr = (_ref = this.expression) != null ? _ref.makeReturn() : void 0;
@@ -1445,7 +1449,7 @@
         if (node.jumps({
           loop: true
         })) {
-          return true;
+          return node;
         }
       }
       return false;
@@ -1795,6 +1799,9 @@
       var body, defPart, forPart, guardPart, idt1, index, ivar, lastJumps, lvar, name, namePart, ref, resultPart, returnResult, rvar, scope, source, stepPart, svar, varPart, _ref;
       body = Expressions.wrap([this.body]);
       lastJumps = (_ref = last(body.expressions)) != null ? _ref.jumps() : void 0;
+      if (lastJumps && lastJumps instanceof Return) {
+        this.returns = false;
+      }
       source = this.range ? this.source.base : this.source;
       scope = o.scope;
       name = this.name && this.name.compile(o, LEVEL_LIST);
@@ -1809,7 +1816,7 @@
           immediate: true
         });
       }
-      if (this.returns && !lastJumps) {
+      if (this.returns) {
         rvar = scope.freeVariable('results');
       }
       ivar = (this.range ? name : index) || scope.freeVariable('i');
@@ -1843,7 +1850,7 @@
           forPart = "" + ivar + " = 0, " + lvar + " = " + svar + ".length; " + ivar + " < " + lvar + "; " + stepPart;
         }
       }
-      if (this.returns && !lastJumps) {
+      if (this.returns) {
         resultPart = "" + this.tab + rvar + " = [];\n";
         returnResult = "\n" + this.tab + "return " + rvar + ";";
         body = Push.wrap(rvar, body);
@@ -1931,7 +1938,7 @@
       for (_i = 0, _len = _ref.length; _i < _len; _i++) {
         _ref2 = _ref[_i], conds = _ref2[0], block = _ref2[1];
         if (block.jumps(o)) {
-          return true;
+          return block;
         }
       }
       return (_ref3 = this.otherwise) != null ? _ref3.jumps(o) : void 0;

src/nodes.coffee

@@ -186,7 +186,7 @@ exports.Expressions = class Expressions extends Base
 
   jumps: (o) ->
     for exp in @expressions
-      return true if exp.jumps o
+      return exp if exp.jumps o
 
   # An Expressions node does not return its entire body, rather it
   # ensures that the final expression is returned.
@@ -283,7 +283,7 @@ exports.Literal = class Literal extends Base
 
   jumps: (o) ->
     return no unless @value in ['break', 'continue', 'debugger']
-    not (o and (o.loop or o.block and (@value isnt 'continue')))
+    if not (o and (o.loop or o.block and (@value isnt 'continue'))) then this else no
 
   compile: ->
     if @value.reserved then "\"#{@value}\"" else @value
@@ -302,7 +302,7 @@ exports.Return = class Return extends Base
 
   isStatement:     YES
   makeReturn:      THIS
-  jumps:           YES
+  jumps:           THIS
 
   compile: (o, level) ->
     expr = @expression?.makeReturn()
@@ -1139,7 +1139,7 @@ exports.While = class While extends Base
     {expressions} = @body
     return no unless expressions.length
     for node in expressions
-      return yes if node.jumps loop: yes
+      return node if node.jumps loop: yes
     no
 
   # The main difference from a JavaScript *while* is that the CoffeeScript
@@ -1444,13 +1444,14 @@ exports.For = class For extends Base
   compileNode: (o) ->
     body          = Expressions.wrap [@body]
     lastJumps     = last(body.expressions)?.jumps()
+    @returns      = no if lastJumps and lastJumps instanceof Return
     source        = if @range then @source.base else @source
     scope         = o.scope
     name          = @name  and @name.compile o, LEVEL_LIST
     index         = @index and @index.compile o, LEVEL_LIST
     scope.find(name,  immediate: yes) if name and not @pattern
     scope.find(index, immediate: yes) if index
-    rvar          = scope.freeVariable 'results' if @returns and not lastJumps
+    rvar          = scope.freeVariable 'results' if @returns
     ivar          = (if @range then name else index) or scope.freeVariable 'i'
     name          = ivar if @pattern
     varPart       = ''
@@ -1472,7 +1473,7 @@ exports.For = class For extends Base
         lvar        = scope.freeVariable 'len'
         stepPart    = if @step then "#{ivar} += #{ @step.compile(o, LEVEL_OP) }" else "#{ivar}++"
         forPart     = "#{ivar} = 0, #{lvar} = #{svar}.length; #{ivar} < #{lvar}; #{stepPart}"
-    if @returns and not lastJumps
+    if @returns
       resultPart    = "#{@tab}#{rvar} = [];\n"
       returnResult  = "\n#{@tab}return #{rvar};"
       body          = Push.wrap rvar, body
@@ -1530,7 +1531,7 @@ exports.Switch = class Switch extends Base
 
   jumps: (o = {block: yes}) ->
     for [conds, block] in @cases
-      return yes if block.jumps o
+      return block if block.jumps o
     @otherwise?.jumps o
 
   makeReturn: ->

test/test_comprehensions.coffee

@@ -279,3 +279,10 @@ result = try
   i
 
 eq result, 10
+
+
+# Comprehensions over break.
+arrayEq (break for [1..10]), []
+
+# Comprehensions over continue.
+arrayEq (break for [1..10]), []

test/test_while.coffee

@@ -51,3 +51,21 @@ ok list.join(' ') is '8 6 4 2'
 
 #759: `if` within `while` condition
 2 while if 1 then 0
+
+
+# While over break.
+i = 0
+result = while i < 10
+  i++
+  break
+
+arrayEq result, []
+
+
+# While over continue.
+i = 0
+result = while i < 10
+  i++
+  continue
+
+arrayEq result, []