From 5612a59b30cb06d6230d571f4ada741bdec5bc95 Mon Sep 17 00:00:00 2001
From: Jeremy Ashkenas <jashkenas@gmail.com>
Date: Sun, 13 Jun 2010 01:13:52 -0400
Subject: [PATCH] allowing implicit returns to be pushed down into each branch
 of computation, even when there's an explicit return nested more deeply.
 Issue #401

---
 lib/nodes.js             | 23 +++++++++++++----------
 src/nodes.coffee         |  5 ++++-
 test/test_returns.coffee | 13 ++++++++++++-
 3 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/lib/nodes.js b/lib/nodes.js
index d4b19e91..28111258 100644
--- a/lib/nodes.js
+++ b/lib/nodes.js
@@ -151,23 +151,24 @@
       }).call(this).join('');
     };
     BaseNode.prototype.eachChild = function(func) {
-      var _b, _c, _d, _e, _f, _g, attr, child;
+      var _b, _c, _d, _e, _f, _g, _h, attr, child;
       if (!(this.children)) {
         return null;
       }
-      _c = this.children;
-      for (_b = 0, _d = _c.length; _b < _d; _b++) {
-        attr = _c[_b];
+      _b = []; _d = this.children;
+      for (_c = 0, _e = _d.length; _c < _e; _c++) {
+        attr = _d[_c];
         if (this[attr]) {
-          _f = flatten([this[attr]]);
-          for (_e = 0, _g = _f.length; _e < _g; _e++) {
-            child = _f[_e];
+          _g = flatten([this[attr]]);
+          for (_f = 0, _h = _g.length; _f < _h; _f++) {
+            child = _g[_f];
             if (func(child) === false) {
               return null;
             }
           }
         }
       }
+      return _b;
     };
     BaseNode.prototype.collectChildren = function() {
       var nodes;
@@ -253,9 +254,8 @@
       if (!last || last instanceof ReturnNode) {
         return this;
       }
-      if (!(last.containsPureStatement())) {
-        this.expressions[idx] = last.makeReturn();
-      }
+      this.expressions[idx] = last.makeReturn();
+      // unless last.containsPureStatement()
       return this;
     };
     // An **Expressions** is the only node that can serve as the root.
@@ -378,6 +378,9 @@
     ReturnNode.prototype.topSensitive = function() {
       return true;
     };
+    ReturnNode.prototype.makeReturn = function() {
+      return this;
+    };
     ReturnNode.prototype.compileNode = function(o) {
       var expr;
       expr = this.expression.makeReturn();
diff --git a/src/nodes.coffee b/src/nodes.coffee
index 08fb8cea..54c632c5 100644
--- a/src/nodes.coffee
+++ b/src/nodes.coffee
@@ -179,7 +179,7 @@ exports.Expressions: class Expressions extends BaseNode
     last: @expressions[idx]
     last: @expressions[idx: - 1] if last instanceof CommentNode
     return this if not last or last instanceof ReturnNode
-    @expressions[idx]: last.makeReturn() unless last.containsPureStatement()
+    @expressions[idx]: last.makeReturn()
     this
 
   # An **Expressions** is the only node that can serve as the root.
@@ -264,6 +264,9 @@ exports.ReturnNode: class ReturnNode extends BaseNode
   topSensitive: ->
     true
 
+  makeReturn: ->
+    this
+
   compileNode: (o) ->
     expr: @expression.makeReturn()
     return expr.compile(o) unless expr instanceof ReturnNode
diff --git a/test/test_returns.coffee b/test/test_returns.coffee
index dd3f3a4d..e074f8e9 100644
--- a/test/test_returns.coffee
+++ b/test/test_returns.coffee
@@ -10,4 +10,15 @@ third: ->
 
 ok first().join(' ')     is 'do do do'
 ok second()[0].join(' ') is 're re re'
-ok third().join(' ')     is 'mi mi mi'
\ No newline at end of file
+ok third().join(' ')     is 'mi mi mi'
+
+
+# Testing returns with multiple branches.
+func: ->
+  if false
+    for a in b
+      return c if d
+  else
+    "word"
+
+ok func() is 'word'
\ No newline at end of file