1 ! Copyright (C) 2008 Doug Coleman.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: classes classes.algebra classes.predicate kernel
7 PREDICATE: singleton-class < predicate-class
8 [ "predicate-definition" word-prop ]
9 [ [ eq? ] curry ] bi sequence= ;
11 : define-singleton-class ( word -- )
12 \ word over [ eq? ] curry define-predicate-class ;
14 M: singleton-class instance? eq? ;
16 M: singleton-class (classes-intersect?)
17 over singleton-class? [ eq? ] [ call-next-method ] if ;