lexers/man.lua

   1 -- Copyright 2015-2016 David B. Lamkins <david@lamkins.net>. See LICENSE.
   2 -- man/roff 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 = 'man'}
   9
  10 -- Whitespace.
  11 local ws = token(l.WHITESPACE, l.space^1)
  12
  13 -- Markup.
  14 local rule1 = token(l.STRING,
  15                     P('.') * (P('B') * P('R')^-1 + P('I') * P('PR')^-1) *
  16                     l.nonnewline^0)
  17 local rule2 = token(l.NUMBER, P('.') * S('ST') * P('H') * l.nonnewline^0)
  18 local rule3 = token(l.KEYWORD,
  19                     P('.br') + P('.DS') + P('.RS') + P('.RE') + P('.PD'))
  20 local rule4 = token(l.LABEL, P('.') * (S('ST') * P('H') + P('.TP')))
  21 local rule5 = token(l.VARIABLE,
  22                     P('.B') * P('R')^-1 + P('.I') * S('PR')^-1 + P('.PP'))
  23 local rule6 = token(l.TYPE, P('\\f') * S('BIPR'))
  24 local rule7 = token(l.PREPROCESSOR, l.starts_line('.') * l.alpha^1)
  25
  26 M._rules = {
  27   {'whitespace', ws},
  28   {'rule1', rule1},
  29   {'rule2', rule2},
  30   {'rule3', rule3},
  31   {'rule4', rule4},
  32   {'rule5', rule5},
  33   {'rule6', rule6},
  34   {'rule7', rule7},
  35 }
  36
  37 return M