lexers/diff.lua

   1 -- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
   2 -- Diff LPeg lexer.
   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 = 'diff'}
   9
  10 -- Text, separators, and file headers.
  11 local index = token(l.COMMENT, 'Index: ' * l.any^0 * P(-1))
  12 local separator = token(l.COMMENT, ('---' + P('*')^4 + P('=')^1) * l.space^0 *
  13                                    -1)
  14 local header = token('header', (P('*** ') + '--- ' + '+++ ') * l.any^1)
  15
  16 -- Location.
  17 local location = token(l.NUMBER, ('@@' + l.digit^1 + '****') * l.any^1)
  18
  19 -- Additions, deletions, and changes.
  20 local addition = token('addition', S('>+') * l.any^0)
  21 local deletion = token('deletion', S('<-') * l.any^0)
  22 local change   = token('change', '! ' * l.any^0)
  23
  24 M._rules = {
  25   {'index', index},
  26   {'separator', separator},
  27   {'header', header},
  28   {'location', location},
  29   {'addition', addition},
  30   {'deletion', deletion},
  31   {'change', change},
  32   {'any_line', token('default', l.any^1)},
  33 }
  34
  35 M._tokenstyles = {
  36   header = l.STYLE_COMMENT,
  37   addition = 'fore:green',
  38   deletion = 'fore:red',
  39   change = 'fore:yellow',
  40 }
  41
  42 M._LEXBYLINE = true
  43
  44 return M