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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2006-2007, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala.util.parsing.json
import scala.util.parsing.combinator._
import scala.util.parsing.combinator.syntactical._
import scala.util.parsing.combinator.lexical._
/**
* @author Derek Chen-Becker <"java"+@+"chen-becker"+"."+"org">
*/
class Parser extends StdTokenParsers with ImplicitConversions {
// Fill in abstract defs
type Tokens = Lexer
val lexical = new Tokens
// Configure lexical parsing
lexical.reserved ++= List("true", "false", "null")
lexical.delimiters ++= List("{", "}", "[", "]", ":", ",")
/** Type signature for functions that can parse numeric literals */
type NumericParser = String => Any
// Global default number parsing function
protected var defaultNumberParser : NumericParser = {_.toDouble}
// Per-thread default number parsing function
protected val numberParser = new ThreadLocal[NumericParser]() {
override def initialValue() = defaultNumberParser
}
// Define the grammar
def root = jsonObj | jsonArray
def jsonObj = "{" ~> repsep(objEntry, ",") <~ "}"
def jsonArray = "[" ~> repsep(value, ",") <~ "]"
def objEntry = stringVal ~ (":" ~> value) ^^ { case x ~ y => (x, y) }
def value: Parser[Any] = (jsonObj | jsonArray | number | "true" ^^^ true | "false" ^^^ false | "null" ^^^ null | stringVal)
def stringVal = accept("string", { case lexical.StringLit(n) => n} )
def number = accept("number", { case lexical.NumericLit(n) => numberParser.get.apply(n)} )
}
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