factor/extra/classes/singleton/singleton.factor

23 lines
664 B
Factor
Executable File

! Copyright (C) 2008 Doug Coleman.
! See http://factorcode.org/license.txt for BSD license.
USING: classes.predicate kernel namespaces parser quotations
sequences words prettyprint prettyprint.backend prettyprint.sections
compiler.units classes ;
IN: classes.singleton
PREDICATE: singleton < predicate-class
[ "predicate-definition" word-prop ]
[ [ eq? ] curry ] bi sequence= ;
: define-singleton ( token -- )
create-class-in
dup save-location
\ singleton
over [ eq? ] curry define-predicate-class ;
: SINGLETON:
scan define-singleton ; parsing
M: singleton see-class* ( class -- )
<colon \ SINGLETON: pprint-word pprint-word ;