60 lines
1.8 KiB
Factor
60 lines
1.8 KiB
Factor
! (c)2009 Joe Groff bsd license
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USING: accessors arrays classes classes.mixin classes.parser
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classes.singleton classes.tuple classes.tuple.parser
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classes.union combinators inverse kernel lexer macros make
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parser quotations sequences slots splitting words ;
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IN: variants
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PREDICATE: variant-class < mixin-class "variant" word-prop ;
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M: variant-class initial-value*
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dup members [ no-initial-value ]
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[ nip first dup word? [ initial-value* ] unless ] if-empty ;
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: define-tuple-class-and-boa-word ( class superclass slots -- )
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pick [ define-tuple-class ] dip
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dup name>> "<" ">" surround create-in swap define-boa-word ;
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: define-variant-member ( member -- class )
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dup array? [ first3 pick [ define-tuple-class-and-boa-word ] dip ] [ dup define-singleton-class ] if ;
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: define-variant-class ( class members -- )
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[ [ define-mixin-class ] [ t "variant" set-word-prop ] [ ] tri ] dip
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[ define-variant-member swap add-mixin-instance ] with each ;
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: parse-variant-tuple-member ( name -- member )
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create-class-in tuple
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"{" expect
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[ "}" parse-tuple-slots-delim ] { } make
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3array ;
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: parse-variant-member ( name -- member )
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":" ?tail [ parse-variant-tuple-member ] [ create-class-in ] if ;
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: parse-variant-members ( -- members )
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[ scan dup ";" = not ]
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[ parse-variant-member ] produce nip ;
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SYNTAX: VARIANT:
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CREATE-CLASS
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parse-variant-members
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define-variant-class ;
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MACRO: unboa ( class -- )
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<wrapper> \ boa [ ] 2sequence [undo] ;
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GENERIC# (match-branch) 1 ( class quot -- class quot' )
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M: singleton-class (match-branch)
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\ drop prefix ;
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M: object (match-branch)
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over \ unboa [ ] 2sequence prepend ;
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: ?class ( object -- class )
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dup word? [ class ] unless ;
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MACRO: match ( branches -- )
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[ dup callable? [ first2 (match-branch) 2array ] unless ] map
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[ \ dup \ ?class ] dip \ case [ ] 4sequence ;
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