Began implementing virtual trait methods

These require special treatment with proxying.

lib/MemberBuilder.js

@@ -135,7 +135,7 @@ exports.buildMethod = function(
     );
 
     // we might be overriding an existing method
-    if ( keywords[ 'proxy' ] )
+    if ( keywords[ 'proxy' ] && !( prev && keywords.weak ) )
     {
         // TODO: Note that this is not compatible with method hiding, due to its
         // positioning (see hideMethod() below); address once method hiding is

lib/MemberBuilderValidator.js

@@ -231,20 +231,32 @@ exports.prototype.validateMethod = function(
             );
         }
 
-        var lenprev = prev,
+
-            lennow  = value;
+        var lenprev = ( prev.__length === undefined )
+            ? prev.length
+            : prev.__length;
+
+        var lennow = ( value.__length === undefined )
+            ? value.length
+            : value.__length;
+
+        if ( keywords[ 'proxy' ] )
+        {
+            // otherwise we'd be checking against the length of a string.
+            lennow = NaN;
+        }
+
         if ( keywords.weak && !( prev_keywords[ 'abstract' ] ) )
         {
             // weak abstract declaration found after its concrete
             // definition; check in reverse order
-            lenprev = value;
+            var tmp = lenprev;
-            lennow  = prev;
+            lenprev = lennow;
+            lennow = tmp;
         }
 
         // ensure parameter list is at least the length of its supertype
-        if ( ( lennow.__length || lennow.length )
+        if ( lennow < lenprev )
-            < ( lenprev.__length || lenprev.length )
-        )
         {
             throw TypeError(
                 "Declaration of method '" + name + "' must be compatible " +

lib/MethodWrappers.js

@@ -127,7 +127,7 @@ exports.standard = {
         // implementations of abstract methods with param requirements (we
         // have no idea what we'll be proxying to at runtime, so we need to
         // just power through it; see test case for more info)
-        ret.__length = Infinity;
+        ret.__length = NaN;
         return ret;
     },
 };

lib/Trait.js

@@ -189,7 +189,8 @@ function mixMethods( src, dest, vis, iname )
             continue;
         }
 
-        var keywords = src[ f ].___$$keywords$$;
+        var keywords = src[ f ].___$$keywords$$,
+            vis      = keywords['protected'] ? 'protected' : 'public';
 
         // if abstract, then we are expected to provide the implementation;
         // otherwise, we proxy to the trait's implementation
@@ -199,12 +200,12 @@ function mixMethods( src, dest, vis, iname )
             // param names, since that is not [yet] important); the
             // visibility modified is important to prevent de-escalation
             // errors on override
-            var vis = keywords['protected'] ? 'protected' : 'public';
             dest[ vis + ' weak abstract ' + f ] = src[ f ].definition;
         }
         else
         {
-            var pname = vis + ' proxy ' + f;
+            var virt  = keywords['virtual'] ? 'weak virtual ' : '',
+                pname = virt + vis + ' proxy ' + f;
 
             // if we have already set up a proxy for a field of this name,
             // then multiple traits have defined the same concrete member

test/MethodWrappersTest.js

@@ -409,7 +409,7 @@ require( 'common' ).testCase(
             {}, null, 0, function() {}, '', {}
         );
 
-        this.assertEqual( f.__length, Infinity );
+        this.assertOk( !( 0 < f.__length ) );
     },
 } );
 

test/Trait/VirtualTest.js

@@ -0,0 +1,100 @@
+/**
+ * Tests virtual trait methods
+ *
+ *  Copyright (C) 2014 Mike Gerwitz
+ *
+ *  This file is part of GNU ease.js.
+ *
+ *  ease.js is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+require( 'common' ).testCase(
+{
+    caseSetUp: function()
+    {
+        this.Sut   = this.require( 'Trait' );
+        this.Class = this.require( 'class' );
+    },
+
+
+    /**
+     * If a trait specifies a virtual method, then the class should expose
+     * the method as virtual.
+     */
+    'Class inherits virtual trait method': function()
+    {
+        var expected = 'foobar';
+
+        var T = this.Sut(
+        {
+            'virtual foo': function()
+            {
+                return expected;
+            }
+        } );
+
+        var C = this.Class.use( T ).extend( {} );
+
+        // ensure that we are actually using the method
+        this.assertEqual( C().foo(), expected );
+
+        // if virtual, we should be able to override it
+        var expected2 = 'foobaz',
+            C2;
+
+        this.assertDoesNotThrow( function()
+        {
+            C2 = C.extend(
+            {
+                'override foo': function()
+                {
+                    return expected2;
+                }
+            } );
+        } );
+
+        this.assertEqual( C2().foo(), expected2 );
+    },
+
+
+    /**
+     * Virtual trait methods should be treated in a manner similar to
+     * abstract trait methods---a class should be able to provide its own
+     * concrete implementation. Note that this differs from the above test
+     * because we are overriding the method internally at definition time,
+     * not subclassing.
+     */
+    'Class can override virtual trait method': function()
+    {
+        var _self = this;
+        var T = this.Sut(
+        {
+            'virtual foo': function()
+            {
+                // we should never execute this (unless we're broken)
+                _self.fail( true, false,
+                    "Method was not overridden."
+                );
+            }
+        } );
+
+        var expected = 'foobar';
+        var C = this.Class.use( T ).extend(
+        {
+            'override foo': function() { return expected; }
+        } );
+
+        this.assertEqual( C().foo(), expected );
+    },
+} );