Removed unprocessed values on a for loop from the grammar.

lib/grammar.js

@@ -187,6 +187,7 @@
         return new SplatNode($1);
       })
     ],
+    // Variables and properties that can be assigned to.
     SimpleAssignable: [o("Identifier", function() {
         return new ValueNode($1);
       }), o("Value Accessor", function() {
@@ -285,6 +286,7 @@
         return $2.new_instance();
       }), o("Super")
     ],
+    // Binds a function call to a context and/or arguments.
     Curry: [o("Value <- Arguments", function() {
         return new CurryNode($1, $3);
       })
@@ -448,7 +450,7 @@
       })
     ],
     // The source of a comprehension is an array or object with an optional filter
-    // clause. If it's an array comprehension, you can also choose to step throug
+    // clause. If it's an array comprehension, you can also choose to step through
     // in fixed-size increments.
     ForSource: [o("IN Expression", function() {
         return {
@@ -459,12 +461,34 @@
           source: $2,
           object: true
         };
-      }), o("ForSource WHEN Expression", function() {
+      }), o("IN Expression WHEN Expression", function() {
-        $1.filter = $3;
+        return {
-        return $1;
+          source: $2,
-      }), o("ForSource BY Expression", function() {
+          filter: $4
-        $1.step = $3;
+        };
-        return $1;
+      }), o("OF Expression WHEN Expression", function() {
+        return {
+          source: $2,
+          filter: $4,
+          object: true
+        };
+      }), o("IN Expression BY Expression", function() {
+        return {
+          source: $2,
+          step: $4
+        };
+      }), o("IN Expression WHEN Expression BY Expression", function() {
+        return {
+          source: $2,
+          filter: $4,
+          step: $6
+        };
+      }), o("IN Expression BY Expression WHEN Expression", function() {
+        return {
+          source: $2,
+          step: $4,
+          filter: $6
+        };
       })
     ],
     // The CoffeeScript switch/when/else block replaces the JavaScript

src/grammar.coffee

@@ -195,6 +195,7 @@ grammar: {
     o "Expression . . .",                       -> new SplatNode $1
   ]
   
+  # Variables and properties that can be assigned to.
   SimpleAssignable: [
     o "Identifier",                             -> new ValueNode $1
     o "Value Accessor",                         -> $1.push $2
@@ -278,6 +279,7 @@ grammar: {
     o "Super"
   ]
 
+  # Binds a function call to a context and/or arguments.
   Curry: [
     o "Value <- Arguments",                     -> new CurryNode $1, $3
   ]
@@ -420,13 +422,16 @@ grammar: {
   ]
 
   # The source of a comprehension is an array or object with an optional filter
-  # clause. If it's an array comprehension, you can also choose to step throug
+  # clause. If it's an array comprehension, you can also choose to step through
   # in fixed-size increments.
   ForSource: [
-    o "IN Expression",                          -> {source:   $2}
+    o "IN Expression",                               -> {source: $2}
-    o "OF Expression",                          -> {source:   $2, object: true}
+    o "OF Expression",                               -> {source: $2, object: true}
-    o "ForSource WHEN Expression",              -> $1.filter: $3; $1
+    o "IN Expression WHEN Expression",               -> {source: $2, filter: $4}
-    o "ForSource BY Expression",                -> $1.step:   $3; $1
+    o "OF Expression WHEN Expression",               -> {source: $2, filter: $4, object: true}
+    o "IN Expression BY Expression",                 -> {source: $2, step:   $4}
+    o "IN Expression WHEN Expression BY Expression", -> {source: $2, filter: $4; step:   $6}
+    o "IN Expression BY Expression WHEN Expression", -> {source: $2, step:   $4, filter: $6}
   ]
 
   # The CoffeeScript switch/when/else block replaces the JavaScript