lexers/context.lua

   1 -- Copyright 2006-2013 Robert Gieseke. See LICENSE.
   2 -- ConTeXt 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 = 'context'}
   9
  10 -- Whitespace.
  11 local ws = token(l.WHITESPACE, l.space^1)
  12
  13 -- Comments.
  14 local comment = token(l.COMMENT, '%' * l.nonnewline^0)
  15
  16 -- Commands.
  17 local command = token(l.KEYWORD, '\\' * (l.alpha^1 + S('#$&~_^%{}')))
  18
  19 -- Sections.
  20 local section = token('section', '\\' * word_match{
  21   'part', 'chapter', 'section', 'subsection', 'subsubsection', 'title',
  22   'subject', 'subsubject', 'subsubsubject'
  23 })
  24
  25 -- ConTeXt environments.
  26 local environment = token('environment', '\\' * (P('start') + 'stop') * l.word)
  27
  28 -- Operators.
  29 local operator = token(l.OPERATOR, S('$&#{}[]'))
  30
  31 M._rules = {
  32   {'whitespace', ws},
  33   {'comment', comment},
  34   {'environment', environment},
  35   {'section', section},
  36   {'keyword', command},
  37   {'operator', operator},
  38 }
  39
  40 M._tokenstyles = {
  41   environment = l.STYLE_KEYWORD,
  42   section = l.STYLE_CLASS
  43 }
  44
  45 M._foldsymbols = {
  46   _patterns = {'\\start', '\\stop', '[{}]', '%%'},
  47   ['environment'] = {['\\start'] = 1, ['\\stop'] = -1},
  48   [l.OPERATOR] = {['{'] = 1, ['}'] = -1},
  49   [l.COMMENT] = {['%'] = l.fold_line_comments('%')}
  50 }
  51
  52 -- Embedded Lua.
  53 local luatex = l.load('lua')
  54 local luatex_start_rule = #P('\\startluacode') * environment
  55 local luatex_end_rule = #P('\\stopluacode') * environment
  56 l.embed_lexer(M, luatex, luatex_start_rule, luatex_end_rule)
  57
  58
  59 return M