Add syntax-pack and grouped to ebnf refactoring
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708d55fb8e
commit
9403d97e22
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@ -104,6 +104,11 @@ DEFER: 'rhs'
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#! does not put the result in the AST.
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token sp hide ;
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: syntax-pack ( begin parser end -- parser )
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#! Parse 'parser' surrounded by syntax elements
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#! begin and end.
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[ syntax ] dipd syntax pack ;
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: 'identifier' ( -- parser )
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#! Return a parser that parses an identifer delimited by
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#! a quotation character. The quotation can be single
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@ -147,26 +152,20 @@ DEFER: 'rhs'
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DEFER: 'choice'
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: grouped ( begin quot end -- parser )
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#! Parse a group of choices, where the delimiter for the
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#! group is specified by 'begin' and 'end'. The quotation
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#! should produce the AST to be the result of the parser.
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[ [ 'choice' sp ] delay swap action ] dip syntax-pack ;
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: 'group' ( -- parser )
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[
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"(" syntax ,
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[ 'choice' sp ] delay ,
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")" syntax ,
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] seq* [ first ] action ;
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"(" [ ] ")" grouped ;
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: 'repeat0' ( -- parser )
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[
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"{" syntax ,
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[ 'choice' sp ] delay ,
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"}" syntax ,
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] seq* [ first <ebnf-repeat0> ] action ;
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"{" [ <ebnf-repeat0> ] "}" grouped ;
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: 'optional' ( -- parser )
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[
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"[" syntax ,
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[ 'choice' sp ] delay ,
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"]" syntax ,
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] seq* [ first <ebnf-optional> ] action ;
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"[" [ <ebnf-optional> ] "]" grouped ;
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: 'sequence' ( -- parser )
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[
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@ -174,14 +173,14 @@ DEFER: 'choice'
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'group' sp ,
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'repeat0' sp ,
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'optional' sp ,
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] choice* repeat1 [
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] choice* repeat1 [
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dup length 1 = [ first ] [ <ebnf-sequence> ] if
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] action ;
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] action ;
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: 'choice' ( -- parser )
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'sequence' sp "|" token sp list-of [
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dup length 1 = [ first ] [ <ebnf-choice> ] if
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] action ;
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] action ;
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: 'action' ( -- parser )
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[
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