lua/lexers/faust.lua

   1 -- Copyright 2015-2017 David B. Lamkins <david@lamkins.net>. See LICENSE.
   2 -- Faust LPeg lexer, see http://faust.grame.fr/
   3
   4 local l = require('lexer')
   5 local token, word_match = l.token, l.word_match
   6 local P, R, S = lpeg.P, lpeg.R, lpeg.S
   7
   8 local M = {_NAME = 'faust'}
   9
  10 -- Whitespace.
  11 local ws = token(l.WHITESPACE, l.space^1)
  12
  13 -- Comments.
  14 local line_comment = '//' * l.nonnewline^0
  15 local block_comment = '/*' * (l.any - '*/')^0 * P('*/')^-1
  16 local comment = token(l.COMMENT, line_comment + block_comment)
  17
  18 -- Strings.
  19 local string = token(l.STRING, l.delimited_range('"', true))
  20
  21 -- Numbers.
  22 local int = R('09')^1
  23 local rad = P('.')
  24 local exp = (P('e') * S('+-')^-1 * int)^-1
  25 local flt = int * (rad * int)^-1 * exp + int^-1 * rad * int * exp
  26 local number = token(l.NUMBER, flt + int)
  27
  28 -- Keywords.
  29 local keyword = token(l.KEYWORD, word_match{
  30   'declare', 'import', 'mdoctags', 'dependencies', 'distributed', 'inputs',
  31   'outputs', 'par', 'seq', 'sum', 'prod', 'xor', 'with', 'environment',
  32   'library', 'component', 'ffunction', 'fvariable', 'fconstant', 'int', 'float',
  33   'case', 'waveform', 'h:', 'v:', 't:'
  34 })
  35
  36 -- Identifiers.
  37 local identifier = token(l.IDENTIFIER, l.word)
  38
  39 -- Operators.
  40 local punct = S('+-/*%<>~!=^&|?~:;,.()[]{}@#$`\\\'')
  41 local operator = token(l.OPERATOR, punct)
  42
  43 -- Pragmas.
  44 local mdoc = P('<mdoc>') * (l.any - P('</mdoc>'))^0 * P('</mdoc>')
  45 local pragma = token(l.PREPROCESSOR, mdoc)
  46
  47 M._rules = {
  48   {'whitespace', ws},
  49   {'comment', comment},
  50   {'pragma', pragma},
  51   {'keyword', keyword},
  52   {'number', number},
  53   {'operator', operator},
  54   {'identifier', identifier},
  55   {'string', string},
  56 }
  57
  58 return M