-- Copyright 2006-2015 Mitchell mitchell.att.foicica.com. See LICENSE. -- Haskell LPeg lexer. -- Modified by Alex Suraci. 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 = 'haskell'} -- Whitespace. local ws = token(l.WHITESPACE, l.space^1) -- Comments. local line_comment = '--' * l.nonnewline_esc^0 local block_comment = '{-' * (l.any - '-}')^0 * P('-}')^-1 local comment = token(l.COMMENT, line_comment + block_comment) -- Strings. local string = token(l.STRING, l.delimited_range('"')) -- Chars. local char = token(l.STRING, l.delimited_range("'", true)) -- Numbers. local number = token(l.NUMBER, l.float + l.integer) -- Keywords. local keyword = token(l.KEYWORD, word_match{ 'case', 'class', 'data', 'default', 'deriving', 'do', 'else', 'if', 'import', 'in', 'infix', 'infixl', 'infixr', 'instance', 'let', 'module', 'newtype', 'of', 'then', 'type', 'where', '_', 'as', 'qualified', 'hiding' }) -- Identifiers. local word = (l.alnum + S("._'#"))^0 local identifier = token(l.IDENTIFIER, (l.alpha + '_') * word) -- Operators. local op = l.punct - S('()[]{}') local operator = token(l.OPERATOR, op) -- Types & type constructors. local constructor = token(l.TYPE, (l.upper * word) + (P(":") * (op^1 - P(":")))) M._rules = { {'whitespace', ws}, {'keyword', keyword}, {'type', constructor}, {'identifier', identifier}, {'string', string}, {'char', char}, {'comment', comment}, {'number', number}, {'operator', operator}, } M._FOLDBYINDENTATION = true return M