47 lines
1.4 KiB
Factor
47 lines
1.4 KiB
Factor
! Copyright (C) 2008 James Cash
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! See http://factorcode.org/license.txt for BSD license.
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USING: kernel peg.ebnf peg.expr math.parser sequences arrays strings combinators.lib
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namespaces combinators math bake ;
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IN: lisp
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TUPLE: lisp-symbol name ;
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C: <symbol> lisp-symbol
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EBNF: lisp-expr
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_ = (" " | "\t" | "\n")*
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LPAREN = "("
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RPAREN = ")"
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digit = [0-9]
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integer = (digit)+ => [[ string>number ]]
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float = (digit)+ "." (digit)* => [[ first3 >string [ >string ] 2 ndip 3append string>number ]]
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number = float
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| integer
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identifier = [a-zA-Z] ([^(){} ])* => [[ [ 1 head ] [ second ] bi append >string <symbol> ]]
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atom = number
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| identifier
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list-item = _ (atom|list) _ => [[ second ]]
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list = LPAREN (list-item)* RPAREN => [[ second ]]
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;EBNF
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DEFER: convert-form
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: convert-body ( lisp-form -- quot )
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[ convert-form ] map [ ] [ compose ] reduce ; inline
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: convert-if ( lisp-form -- quot )
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1 tail [ convert-form ] map reverse first3 [ % , , if ] bake ;
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: convert-general-form ( lisp-form -- quot )
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unclip swap convert-body [ % , ] bake ;
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: convert-list-form ( lisp-form -- quot )
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dup first
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{ { [ dup "if" <symbol> equal? ] [ drop convert-if ] }
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[ drop convert-general-form ]
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} cond ;
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: convert-form ( lisp-form -- quot )
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{ { [ dup [ sequence? ] [ number? not ] bi and ] [ convert-list-form ] }
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[ [ , ] [ ] make ]
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} cond ; |