From 316a7dd703c3adad727e437450cdea8817ff95a9 Mon Sep 17 00:00:00 2001
From: Mike Gerwitz <mikegerwitz@gnu.org>
Date: Tue, 11 Mar 2014 06:36:45 -0400
Subject: [PATCH] Refactored Traits to use propParse hooks

---
 lib/ClassBuilder.js | 39 +++++++++++++++++++++++++---
 lib/Trait.js        | 63 +++++++++++++++++++++++++++++++--------------
 2 files changed, 80 insertions(+), 22 deletions(-)

diff --git a/lib/ClassBuilder.js b/lib/ClassBuilder.js
index b351dd6..5d29a29 100644
--- a/lib/ClassBuilder.js
+++ b/lib/ClassBuilder.js
@@ -487,14 +487,47 @@ exports.prototype.buildMembers = function buildMembers(
         virtual_members:  memberdest['virtual'],
     };
 
-    util.propParse( props, {
+    // default member handlers for parser
+    var handlers = {
         each:     _parseEach,
         property: _parseProp,
         getset:   _parseGetSet,
         method:   _parseMethod,
-    }, context );
+    };
 
-    // process accumulated member state
+    // a custom parser may be provided to hook the below property parser;
+    // this can be done to save time on post-processing, or alter the
+    // default behavior of the parser
+    if ( props.___$$parser$$ )
+    {
+        // this isn't something that we actually want to parse
+        var parser = props.___$$parser$$;
+        delete props.___$$parser$$;
+
+        function hjoin( name, orig )
+        {
+            handlers[ name ] = function()
+            {
+                var args = Array.prototype.slice.call( arguments );
+
+                // invoke the custom handler with the original handler as
+                // its last argument (which the custom handler may choose
+                // not to invoke at all)
+                args.push( orig );
+                parser[ name ].apply( context, args );
+            };
+        }
+
+        // this avoids a performance penalty unless the above property is
+        // set
+        parser.each     && hjoin( 'each', handlers.each );
+        parser.property && hjoin( 'property', handlers.property );
+        parser.getset   && hjoin( 'getset', handlers.getset );
+        parser.method   && hjoin( 'method', handlers.method );
+    }
+
+    // parse members and process accumulated member state
+    util.propParse( props, handlers, context );
     this._memberBuilder.end( context.state );
 }
 
diff --git a/lib/Trait.js b/lib/Trait.js
index 31de351..c2bb77b 100644
--- a/lib/Trait.js
+++ b/lib/Trait.js
@@ -86,6 +86,12 @@ Trait.extend = function( dfn )
     // just in case DFN does not contain any abstract members itself
     dfn[ 'abstract protected ___$$trait$$' ] = [];
 
+    // augment the parser to handle our own oddities
+    dfn.___$$parser$$ = {
+        each:     _parseMember,
+        property: _parseProps,
+    };
+
     // give the abstract trait class a distinctive name for debugging
     dfn.__name = '#AbstractTrait#';
 
@@ -112,16 +118,6 @@ Trait.extend = function( dfn )
         return ''+name;
     };
 
-    // traits are not permitted to define constructors
-    if ( tclass.___$$methods$$['public'].__construct !== undefined )
-    {
-        throw Error( "Traits may not define __construct" );
-    }
-
-    // traits have property restrictions
-    validateProps( tclass.___$$props$$['public'] );
-    validateProps( tclass.___$$props$$['protected'] );
-
     // invoked to trigger mixin
     TraitType.__mixin = function( dfn, tc, base )
     {
@@ -138,30 +134,59 @@ Trait.extend = function( dfn )
 };
 
 
+/**
+ * Verifies trait member restrictions
+ *
+ * @param  {string}   name      property name
+ * @param  {*}        value     property value
+ * @param  {Object}   keywords  property keywords
+ * @param  {Function} h         original handler that we replaced
+ *
+ * @return  {undefined}
+ */
+function _parseMember( name, value, keywords, h )
+{
+    // traits are not permitted to define constructors
+    if ( name === '__construct' )
+    {
+        throw Error( "Traits may not define __construct" );
+    }
+
+    // apply original handler
+    h.apply( this, arguments );
+}
+
+
 /**
  * Throws error if non-internal property is found within PROPS
  *
  * For details and rationale, see the Trait/PropertyTest case.
  *
- * @param  {Object}  props  properties to prohibit
+ * @param  {string}   name      property name
+ * @param  {*}        value     property value
+ * @param  {Object}   keywords  property keywords
+ * @param  {Function} h         original handler that we replaced
  *
  * @return  {undefined}
  */
-function validateProps( props )
+function _parseProps( name, value, keywords, h )
 {
-    for ( var f in props )
+    // ignore internal properties
+    if ( name.substr( 0, 3 ) === '___' )
     {
-        // ignore internal properties
-        if ( f.substr( 0, 3 ) === '___' )
-        {
-            continue;
-        }
+        return;
+    }
 
+    if ( !( keywords['private'] ) )
+    {
         throw Error(
-            "Cannot define property `" + f + "'; only private " +
+            "Cannot define property `" + name + "'; only private " +
             "properties are permitted within Trait definitions"
         );
     }
+
+    // apply original handler
+    h.apply( this, arguments );
 }