1 ! (c)2009 Joe Groff bsd license
2 USING: accessors arrays classes classes.mixin classes.parser
3 classes.singleton classes.tuple classes.tuple.parser
4 classes.union combinators inverse kernel lexer macros make
5 parser quotations sequences slots splitting words ;
8 PREDICATE: variant-class < mixin-class "variant" word-prop ;
10 M: variant-class initial-value*
11 dup members [ no-initial-value ]
12 [ nip first dup word? [ initial-value* ] unless ] if-empty ;
14 : define-tuple-class-and-boa-word ( class superclass slots -- )
15 pick [ define-tuple-class ] dip
16 dup name>> "<" ">" surround create-in swap define-boa-word ;
18 : define-variant-member ( member -- class )
19 dup array? [ first3 pick [ define-tuple-class-and-boa-word ] dip ] [ dup define-singleton-class ] if ;
21 : define-variant-class ( class members -- )
22 [ [ define-mixin-class ] [ t "variant" set-word-prop ] [ ] tri ] dip
23 [ define-variant-member swap add-mixin-instance ] with each ;
25 : parse-variant-tuple-member ( name -- member )
28 [ "}" parse-tuple-slots-delim ] { } make
31 : parse-variant-member ( name -- member )
32 ":" ?tail [ parse-variant-tuple-member ] [ create-class-in ] if ;
34 : parse-variant-members ( -- members )
35 [ scan dup ";" = not ]
36 [ parse-variant-member ] produce nip ;
41 define-variant-class ;
43 MACRO: unboa ( class -- )
44 <wrapper> \ boa [ ] 2sequence [undo] ;
46 GENERIC# (match-branch) 1 ( class quot -- class quot' )
48 M: singleton-class (match-branch)
50 M: object (match-branch)
51 over \ unboa [ ] 2sequence prepend ;
53 : ?class ( object -- class )
54 dup word? [ class ] unless ;
56 MACRO: match ( branches -- )
57 [ dup callable? [ first2 (match-branch) 2array ] unless ] map
58 [ \ dup \ ?class ] dip \ case [ ] 4sequence ;