-- Copyright 2006-2019 Brian "Sir Alaran" Schott. See License.txt.
-- JSON LPeg lexer.
-- Based off of lexer code by Mitchell.

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

local lex = lexer.new('json')

-- Whitespace.
lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))

-- Strings.
lex:add_rule('string', token(lexer.STRING, lexer.delimited_range("'", true) +
                                           lexer.delimited_range('"', true)))

-- Keywords.
lex:add_rule('keyword', token(lexer.KEYWORD, word_match[[true false null]]))

-- Comments.
local line_comment = '//' * lexer.nonnewline_esc^0
local block_comment = '/*' * (lexer.any - '*/')^0 * P('*/')^-1
lex:add_rule('comment', token(lexer.COMMENT, line_comment + block_comment))

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

-- Operators.
lex:add_rule('operator', token(lexer.OPERATOR, S('[]{}:,')))

-- Fold points.
lex:add_fold_point(lexer.OPERATOR, '[', ']')
lex:add_fold_point(lexer.OPERATOR, '{', '}')
lex:add_fold_point(lexer.COMMENT, '/*', '*/')
lex:add_fold_point(lexer.COMMENT, '//', lexer.fold_line_comments('//'))

return lex