25 lines
739 B
Factor
Executable File
25 lines
739 B
Factor
Executable File
! Copyright (C) 2004, 2008 Slava Pestov.
|
|
! See http://factorcode.org/license.txt for BSD license.
|
|
USING: classes kernel namespaces words ;
|
|
IN: classes.predicate
|
|
|
|
PREDICATE: predicate-class < class
|
|
"metaclass" word-prop predicate-class eq? ;
|
|
|
|
: predicate-quot ( class -- quot )
|
|
[
|
|
\ dup ,
|
|
dup superclass "predicate" word-prop %
|
|
"predicate-definition" word-prop , [ drop f ] , \ if ,
|
|
] [ ] make ;
|
|
|
|
: define-predicate-class ( class superclass definition -- )
|
|
>r dupd f predicate-class define-class
|
|
r> dupd "predicate-definition" set-word-prop
|
|
dup predicate-quot define-predicate ;
|
|
|
|
M: predicate-class reset-class
|
|
{
|
|
"metaclass" "predicate-definition" "superclass"
|
|
} reset-props ;
|