factor/library/generic/complement.factor

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Factor

! Copyright (C) 2005 Slava Pestov.
! See http://factor.sf.net/license.txt for BSD license.
IN: generic
USING: errors hashtables kernel lists math parser strings
sequences vectors words ;
! Complement metaclass, contains all objects not in a certain class.
SYMBOL: complement
complement [
"complement" word-prop builtin-supertypes
num-types count
difference
] "builtin-supertypes" set-word-prop
complement [
( generic vtable definition class -- )
drop num-types [
[
>r 3dup r> builtin-type
dup [ add-method ] [ 2drop 2drop ] ifte
] keep
] repeat 3drop
] "add-method" set-word-prop
complement 90 "priority" set-word-prop
complement [
swap "complement" word-prop
swap "complement" word-prop
class< not
] "class<" set-word-prop
: complement-predicate ( complement -- list )
"predicate" word-prop [ not ] append ;
: define-complement ( class complement -- )
2dup "complement" set-word-prop
dupd complement-predicate "predicate" set-word-prop
complement define-class ;
PREDICATE: word complement metaclass complement = ;