! :folding=indent:collapseFolds=1:

! $Id$
!
! Copyright (C) 2004 Slava Pestov.
! 
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! modification, are permitted provided that the following conditions are met:
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IN: generic
USE: errors
USE: hashtables
USE: kernel
USE: lists
USE: namespaces
USE: parser
USE: strings
USE: words
USE: vectors

! Builtin metaclass for builtin types: fixnum, word, cons, etc.
SYMBOL: builtin

builtin [
    "builtin-type" word-property unit
] "builtin-supertypes" set-word-property

builtin [
    ( generic vtable definition class -- )
    rot set-vtable drop
] "add-method" set-word-property

builtin 50 "priority" set-word-property

! All builtin types are equivalent in ordering
builtin [ 2drop t ] "class<" set-word-property

: builtin-predicate ( type# symbol -- )
    #! We call search here because we have to know if the symbol
    #! is t or f, and cannot compare type numbers or symbol
    #! identity during bootstrapping.
    dup "f" [ "syntax" ] search = [
        nip [ not ] "predicate" set-word-property
    ] [
        dup "t" [ "syntax" ] search = [
            nip [ ] "predicate" set-word-property
        ] [
            dup predicate-word
            [ rot [ swap type eq? ] cons define-compound ] keep
            unit "predicate" set-word-property
        ] ifte
    ] ifte ;

: builtin-class ( type# symbol -- )
    dup intern-symbol
    2dup builtin-predicate
    [ swap "builtin-type" set-word-property ] keep
    builtin define-class ;

: BUILTIN:
    #! Followed by type name and type number. Define a built-in
    #! type predicate with this number.
    CREATE scan-word swap builtin-class ; parsing

: builtin-type ( n -- symbol )
    unit classes get hash ;

M: object class ( obj -- class )
    #! Analogous to the type primitive. Pushes the builtin
    #! class of an object.
    type builtin-type ;