61 lines
1.6 KiB
Factor
61 lines
1.6 KiB
Factor
! Copyright (C) 2008 Peter Burns.
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! See http://factorcode.org/license.txt for BSD license.
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USING: kernel peg peg.ebnf math.parser math.parser.private strings math
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math.functions sequences arrays vectors hashtables assocs
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prettyprint json ;
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IN: json.reader
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<PRIVATE
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: grammar-list>vector ( seq -- vec ) first2 values swap prefix ;
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! Grammar for JSON from RFC 4627
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EBNF: (json>)
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ws = (" " | "\r" | "\t" | "\n")*
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true = "true" => [[ t ]]
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false = "false" => [[ f ]]
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null = "null" => [[ json-null ]]
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hex = [0-9a-fA-F]
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char = '\\"' [[ CHAR: " ]]
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| "\\\\" [[ CHAR: \ ]]
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| "\\/" [[ CHAR: / ]]
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| "\\b" [[ 8 ]]
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| "\\f" [[ 12 ]]
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| "\\n" [[ CHAR: \n ]]
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| "\\r" [[ CHAR: \r ]]
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| "\\t" [[ CHAR: \t ]]
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| "\\u" (hex hex hex hex) [[ hex> ]] => [[ second ]]
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| [^"\]
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string = '"' char*:cs '"' => [[ cs >string ]]
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sign = ("-" | "+")? => [[ "-" = "-" "" ? ]]
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digits = [0-9]+ => [[ >string ]]
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decimal = "." digits => [[ concat ]]
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exp = ("e" | "E") sign digits => [[ concat ]]
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number = sign digits decimal? exp? => [[ dup concat swap fourth [ string>float ] [ string>number ] if ]]
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elements = value ("," value)* => [[ grammar-list>vector ]]
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array = "[" elements?:arr "]" => [[ arr >array ]]
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pair = ws string:key ws ":" value:val => [[ { key val } ]]
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members = pair ("," pair)* => [[ grammar-list>vector ]]
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object = "{" members?:hash "}" => [[ hash >hashtable ]]
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val = true
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| false
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| null
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| string
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| number
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| array
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| object
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value = ws val:v ws => [[ v ]]
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;EBNF
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PRIVATE>
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: json> ( string -- object ) (json>) ; |