factor/library/generic/builtin.factor

58 lines
1.6 KiB
Factor

! Copyright (C) 2004, 2005 Slava Pestov.
! See http://factor.sf.net/license.txt for BSD license.
IN: generic
USING: errors hashtables kernel lists math namespaces parser
sequences strings vectors words ;
! Builtin metaclass for builtin types: fixnum, word, cons, etc.
SYMBOL: builtin
! Global vector mapping type numbers to builtin class objects.
SYMBOL: builtins
builtin [
"builtin-type" word-prop unit
] "builtin-supertypes" set-word-prop
builtin [
( generic vtable definition class -- )
rot set-vtable drop
] "add-method" set-word-prop
builtin 50 "priority" set-word-prop
! All builtin types are equivalent in ordering
builtin [ 2drop t ] "class<" set-word-prop
: 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-prop
] [
dup "t" [ "syntax" ] search = [
nip [ ] "predicate" set-word-prop
] [
dup predicate-word
[ rot [ swap type eq? ] cons define-compound ] keep
unit "predicate" set-word-prop
] ifte
] ifte ;
: builtin-class ( symbol type# slotspec -- )
>r 2dup builtins get set-nth r>
>r swap
dup intern-symbol
2dup builtin-predicate
[ swap "builtin-type" set-word-prop ] keep
dup builtin define-class r> define-slots ;
: builtin-type ( n -- symbol ) builtins get nth ;
PREDICATE: word builtin metaclass builtin = ;
: type-tag ( type -- tag )
#! Given a type number, return the tag number.
dup 6 > [ drop 3 ] when ;