! Copyright (C) 2004, 2008 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: classes words kernel kernel.private namespaces
sequences math math.private ;
IN: classes.builtin

SYMBOL: builtins

PREDICATE: builtin-class < class
    "metaclass" word-prop builtin-class eq? ;

: type>class ( n -- class ) builtins get-global nth ;

: class>type ( class -- n ) "type" word-prop ; foldable

: bootstrap-type>class ( n -- class ) builtins get nth ;

M: hi-tag class hi-tag type>class ;

M: object class tag type>class ;

M: builtin-class rank-class drop 0 ;

: builtin-instance? ( object n -- ? )
    #! 7 == tag-mask get
    #! 3 == hi-tag tag-number
    dup 7 fixnum<= [ swap tag eq? ] [
        swap dup tag 3 eq?
        [ hi-tag eq? ] [ 2drop f ] if
    ] if ; inline

M: builtin-class instance?
    class>type builtin-instance? ;