# README

JSON

This package is a JSON lexer (ECMA-404) written in Go. It follows the specification at JSON. The lexer takes an io.Reader and converts it into tokens until the EOF.

Installation

Run the following command

go get github.com/tdewolff/parse/json

or add the following import and run project with go get

import "github.com/tdewolff/parse/json"

Parser

Usage

The following initializes a new Parser with io.Reader r:

p := json.NewParser(r)

To tokenize until EOF an error, use:

for {
	gt, text := p.Next()
	switch gt {
	case json.ErrorGrammar:
		// error or EOF set in p.Err()
		return
	// ...
	}
}

All grammars:

ErrorGrammar       GrammarType = iota // extra grammar when errors occur
WhitespaceGrammar                     // space \t \r \n
LiteralGrammar                        // null true false
NumberGrammar
StringGrammar
StartObjectGrammar // {
EndObjectGrammar   // }
StartArrayGrammar  // [
EndArrayGrammar    // ]

Examples

package main

import (
	"os"

	"github.com/tdewolff/parse/json"
)

// Tokenize JSON from stdin.
func main() {
	p := json.NewParser(os.Stdin)
	for {
		gt, text := p.Next()
		switch gt {
		case json.ErrorGrammar:
			if p.Err() != io.EOF {
				fmt.Println("Error on line", p.Line(), ":", p.Err())
			}
			return
		case json.LiteralGrammar:
			fmt.Println("Literal", string(text))
		case json.NumberGrammar:
			fmt.Println("Number", string(text))
		// ...
		}
	}
}