lexers/man.lua

   1 -- man/roff LPeg lexer.
   2
   3 local l = require('lexer')
   4 local token, word_match = l.token, l.word_match
   5 local P, R, S = lpeg.P, lpeg.R, lpeg.S
   6
   7 local M = {_NAME = 'man'}
   8
   9 -- Whitespace.
  10 local ws = token(l.WHITESPACE, l.space^1)
  11
  12 -- Markup.
  13 local rule1 = token(l.STRING,
  14         P('.') * (P('B') * P('R')^-1 + P('I') * P('PR')^-1) * l.nonnewline^0)
  15 local rule2 = token(l.NUMBER, P('.') * S('ST') * P('H') * l.nonnewline^0)
  16 local rule3 = token(l.KEYWORD,
  17         P('.br') + P('.DS') + P('.RS') + P('.RE') + P('.PD'))
  18 local rule4 = token(l.LABEL, P('.') * (S('ST') * P('H') + P('.TP')))
  19 local rule5 = token(l.VARIABLE,
  20         P('.B') * P('R')^-1 + P('.I') * S('PR')^-1 + P('.PP'))
  21 local rule6 = token(l.TYPE, P('\\f') * S('BIPR'))
  22 local rule7 = token(l.PREPROCESSOR, l.starts_line('.') * l.alpha^1)
  23
  24 M._rules = {
  25   {'whitespace', ws},
  26   {'rule1', rule1},
  27   {'rule2', rule2},
  28   {'rule3', rule3},
  29   {'rule4', rule4},
  30   {'rule5', rule5},
  31   {'rule6', rule6},
  32   {'rule7', rule7},
  33 }
  34
  35 return M