delegate: add support for single-generic protocols, add failing unit test for bug

basis/delegate/delegate-tests.factor

@@ -120,3 +120,27 @@ PROTOCOL: silly-protocol do-me ;
 ] unit-test
 
 [ ] [ T{ a-tuple } do-me ] unit-test
+
+! A slot protocol issue
+DEFER: slot-protocol-test-3
+SLOT: y
+
+[ f ] [ \ y>> \ slot-protocol-test-3 method >boolean ] unit-test
+
+[ [ ] ] [
+    <" IN: delegate.tests
+USING: accessors delegate ;
+TUPLE: slot-protocol-test-3 x ;
+CONSULT: y>> slot-protocol-test-3 x>> ;">
+    <string-reader> "delegate-test-1" parse-stream
+] unit-test
+
+[ t ] [ \ y>> \ slot-protocol-test-3 method >boolean ] unit-test
+
+[ [ ] ] [
+    <" IN: delegate.tests
+TUPLE: slot-protocol-test-3 x y ;">
+    <string-reader> "delegate-test-1" parse-stream
+] unit-test
+
+[ t ] [ \ y>> \ slot-protocol-test-3 method >boolean ] unit-test

basis/delegate/delegate.factor

@@ -1,8 +1,10 @@
 ! Copyright (C) 2007, 2008 Daniel Ehrenberg
+! Portions copyright (C) 2009 Slava Pestov
 ! See http://factorcode.org/license.txt for BSD license.
 USING: accessors arrays assocs classes.tuple definitions
-generalizations generic hashtables kernel lexer make math parser
+generalizations generic generic.standard hashtables kernel
-generic.parser sequences sets slots words words.symbol fry ;
+lexer make math parser generic.parser sequences sets slots
+words words.symbol fry ;
 IN: delegate
 
 : protocol-words ( protocol -- words )
@@ -13,6 +15,9 @@ IN: delegate
 
 GENERIC: group-words ( group -- words )
 
+M: standard-generic group-words
+    dup "combination" word-prop #>> 2array 1array ;
+
 M: tuple-class group-words
     all-slots [
         name>>