json.lua

-- Copyright 2006-2013 Brian "Sir Alaran" Schott. See LICENSE.
-- JSON LPeg lexer.
-- Based off of lexer code by Mitchell.

local l = require('lexer')
local token, word_match = l.token, l.word_match
local P, R, S = lpeg.P, lpeg.R, lpeg.S

local M = {_NAME = 'json'}

-- Whitespace.
local ws = token(l.WHITESPACE, l.space^1)

-- Comments.
local comment = token(l.COMMENT, '/*' * (l.any - '*/')^0 * P('*/')^-1)

-- Strings.
local sq_str = P('u')^-1 * l.delimited_range("'", true)
local dq_str = P('U')^-1 * l.delimited_range('"', true)
local string = token(l.STRING, sq_str + dq_str)

-- Numbers.
local integer = S('+-')^-1 * l.digit^1 * S('Ll')^-1
local number = token(l.NUMBER, l.float + integer)

-- Keywords.
local keyword = token(l.KEYWORD, word_match{"true", "false", "null"})

-- Operators.
local operator = token(l.OPERATOR, S('[]{}:,'))

M._rules = {
  {'whitespace', ws},
  {'comment', comment},
  {'string', string},
  {'number', number},
  {'keyword', keyword},
  {'operator', operator},
}

M._foldsymbols = {
  _patterns = {'[%[%]{}]', '/%*', '%*/'},
  [l.OPERATOR] = {['['] = 1, [']'] = -1, ['{'] = 1, ['}'] = -1},
  [l.COMMENT] = {['/*'] = 1, ['*/'] = -1}
}

return M