factor/core/classes/union/union.factor

49 lines
1.3 KiB
Factor

! Copyright (C) 2004, 2010 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: words sequences kernel assocs combinators classes
classes.private classes.algebra classes.algebra.private
namespaces arrays math quotations definitions ;
IN: classes.union
PREDICATE: union-class < class
"metaclass" word-prop union-class eq? ;
<PRIVATE
: union-predicate-quot ( members -- quot )
[
[ drop f ]
] [
unclip "predicate" word-prop swap [
"predicate" word-prop [ dup ] prepend
[ drop t ]
] { } map>assoc alist>quot
] if-empty ;
: define-union-predicate ( class -- )
dup members union-predicate-quot define-predicate ;
M: union-class update-class define-union-predicate ;
: (define-union-class) ( class members -- )
f swap f union-class make-class-props (define-class) ;
PRIVATE>
: define-union-class ( class members -- )
[ (define-union-class) ]
[ drop changed-conditionally ]
[ drop update-classes ]
2tri ;
M: union-class rank-class drop 7 ;
M: union-class instance?
"members" word-prop [ instance? ] with any? ;
M: union-class normalize-class
members <anonymous-union> normalize-class ;
M: union-class (flatten-class)
members <anonymous-union> (flatten-class) ;