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 class-members [ f f ] [
12 first dup word? [ t ] [ initial-value* ] if
15 : define-tuple-class-and-boa-word ( class superclass slots -- )
16 pick [ define-tuple-class ] dip
17 dup name>> "<" ">" surround create-word-in swap define-boa-word ;
19 : define-variant-member ( member -- class )
20 dup array? [ first3 pick [ define-tuple-class-and-boa-word ] dip ] [ dup define-singleton-class ] if ;
22 : define-variant-class ( class -- )
23 [ define-mixin-class ] [ t "variant?" set-word-prop ] bi ;
25 : define-variant-class-member ( class member -- )
26 define-variant-member swap add-mixin-instance ;
28 : define-variant-class-members ( class members -- )
29 [ dup define-variant-class ] dip
30 [ define-variant-class-member ] with each ;
32 : parse-variant-tuple-member ( name -- member )
35 [ "}" parse-tuple-slots-delim ] { } make
38 : parse-variant-member ( name -- member )
39 ":" ?tail [ parse-variant-tuple-member ] [ create-class-in ] if ;
41 : parse-variant-members ( -- members )
42 [ scan-token dup ";" = not ]
43 [ parse-variant-member ] produce nip ;
48 define-variant-class-members ;
50 SYNTAX: VARIANT-MEMBER:
52 scan-token parse-variant-member
53 define-variant-class-member ";" expect ;
55 MACRO: unboa ( class -- quot )
56 <wrapper> \ boa [ ] 2sequence [undo] ;
58 GENERIC#: (match-branch) 1 ( class quot -- class quot' )
60 M: singleton-class (match-branch)
62 M: object (match-branch)
63 over \ unboa [ ] 2sequence prepend ;
65 : ?class ( object -- class )
66 dup word? [ class-of ] unless ;
68 MACRO: match ( branches -- quot )
69 [ dup callable? [ first2 (match-branch) 2array ] unless ] map
70 [ \ dup \ ?class ] dip \ case [ ] 4sequence ;