! Copyright (C) 2008 Doug Coleman.
! See http://factorcode.org/license.txt for BSD license.
USING: classes classes.predicate kernel sequences words ;
IN: classes.singleton

PREDICATE: singleton-class < predicate-class
    [ "predicate-definition" word-prop ]
    [ [ eq? ] curry ] bi sequence= ;

: define-singleton-class ( word -- )
    \ word over [ eq? ] curry define-predicate-class ;

M: singleton-class instance? eq? ;