algebraic data types

extra/classes/algebraic/algebraic-docs.factor

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+USING: help.markup help.syntax ;
+IN: classes.algebraic
+HELP: DATA:
+{ $syntax "DATA: class constructor | constructor arg ... | ... ;" }
+{ $description "Creates a haskell style algebraic data type.  For each constructor, a seperate tuple is created, and the resulting tuples are added to a union class." } ;

extra/classes/algebraic/algebraic.factor

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+USING: classes.parser classes.tuple classes.union kernel peg
+peg-lexer sequences ;
+IN: classes.algebraic
+
+ON-BNF: DATA:
+tokenizer = <foreign factor>
+delimit = "|" => [[ drop ignore ]]
+tuple = (!("|"|";").)+ => [[ unclip create-class-in [ tuple rot define-tuple-class ] keep ]]
+expr = . tuple (delimit tuple)* ";" => [[ first3 swap prefix [ create-class-in ] dip define-union-class ignore ]]
+;ON-BNF

extra/classes/algebraic/authors.txt

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+Sam Anklesaria

extra/classes/algebraic/summary.txt

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+Haskell-like algebraic data types