41 lines
1.8 KiB
Factor
41 lines
1.8 KiB
Factor
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! 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 peg.ebnf math.parser sequences arrays strings
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math fry accessors lists combinators.short-circuit ;
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IN: lisp.parser
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TUPLE: lisp-symbol name ;
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C: <lisp-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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dquote = '"'
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squote = "'"
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digit = [0-9]
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integer = ("-")? (digit)+ => [[ first2 append string>number ]]
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float = integer "." (digit)* => [[ first3 >string [ number>string ] 2dip 3append string>number ]]
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rational = integer "/" (digit)+ => [[ first3 nip string>number / ]]
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number = float
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| rational
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| integer
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id-specials = "!" | "$" | "%" | "&" | "*" | "/" | ":"
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| "<" | "#" | " =" | ">" | "?" | "^" | "_"
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| "~" | "+" | "-" | "." | "@"
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letters = [a-zA-Z] => [[ 1array >string ]]
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initials = letters | id-specials
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numbers = [0-9] => [[ 1array >string ]]
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subsequents = initials | numbers
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identifier = initials (subsequents)* => [[ first2 concat append <lisp-symbol> ]]
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escaped = "\" . => [[ second ]]
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string = dquote ( escaped | !(dquote) . )* dquote => [[ second >string ]]
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atom = number
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| identifier
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| string
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s-expression = LPAREN (list-item)* RPAREN => [[ second seq>cons ]]
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list-item = _ ( atom | s-expression | quoted ) _ => [[ second ]]
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quoted = squote list-item => [[ second nil cons "quote" <lisp-symbol> swap cons ]]
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expr = list-item
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;EBNF
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