-- Copyright 2006-2019 Mitchell mitchell.att.foicica.com. See License.txt.
-- SQL LPeg lexer.

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('my')

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

-- Keywords.
lex:add_rule('keyword', token(lexer.KEYWORD, word_match([[
  xxx yyy zzz
]], true)))

-- Identifiers.
lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word))

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

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

-- Numbers.
lex:add_rule('number', token(lexer.NUMBER, lexer.float + lexer.integer))

-- Operators.
lex:add_rule('operator', token(lexer.OPERATOR, S(',()')))

return lex
