factor/core/classes/union/union.factor

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Factor
Executable File

! Copyright (C) 2004, 2007 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: words sequences kernel assocs combinators classes
generic.standard namespaces arrays ;
IN: classes.union
PREDICATE: class union-class
"metaclass" word-prop union-class eq? ;
! Union classes for dispatch on multiple classes.
: union-predicate-quot ( members -- quot )
0 (dispatch#) [
[ [ drop t ] ] { } map>assoc
object bootstrap-word [ drop f ] 2array add*
single-combination
] with-variable ;
: define-union-predicate ( class -- )
dup predicate-word
over members union-predicate-quot
define-predicate ;
M: union-class update-predicate define-union-predicate ;
: define-union-class ( class members -- )
dupd f union-class define-class define-union-predicate ;
M: union-class reset-class
{ "metaclass" "members" } reset-props ;