lexers/vb.lua

   1 -- Copyright 2006-2016 Mitchell mitchell.att.foicica.com. See LICENSE.
   2 -- VisualBasic 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 = 'vb'}
   9
  10 -- Whitespace.
  11 local ws = token(l.WHITESPACE, l.space^1)
  12
  13 -- Comments.
  14 local comment = token(l.COMMENT, (P("'") + word_match({'rem'}, nil, true)) *
  15                                  l.nonnewline^0)
  16
  17 -- Strings.
  18 local string = token(l.STRING, l.delimited_range('"', true, true))
  19
  20 -- Numbers.
  21 local number = token(l.NUMBER, (l.float + l.integer) * S('LlUuFf')^-2)
  22
  23 -- Keywords.
  24 local keyword = token(l.KEYWORD, word_match({
  25   -- Control.
  26   'If', 'Then', 'Else', 'ElseIf', 'While', 'Wend', 'For', 'To', 'Each',
  27   'In', 'Step', 'Case', 'Select', 'Return', 'Continue', 'Do',
  28   'Until', 'Loop', 'Next', 'With', 'Exit',
  29   -- Operators.
  30   'Mod', 'And', 'Not', 'Or', 'Xor', 'Is',
  31   -- Storage types.
  32   'Call', 'Class', 'Const', 'Dim', 'ReDim', 'Preserve', 'Function', 'Sub',
  33   'Property', 'End', 'Set', 'Let', 'Get', 'New', 'Randomize', 'Option',
  34   'Explicit', 'On', 'Error', 'Execute',
  35   -- Storage modifiers.
  36   'Private', 'Public', 'Default',
  37   -- Constants.
  38   'Empty', 'False', 'Nothing', 'Null', 'True'
  39 }, nil, true))
  40
  41 -- Types.
  42 local type = token(l.TYPE, word_match({
  43   'Boolean', 'Byte', 'Char', 'Date', 'Decimal', 'Double', 'Long', 'Object',
  44   'Short', 'Single', 'String'
  45 }, nil, true))
  46
  47 -- Identifiers.
  48 local identifier = token(l.IDENTIFIER, l.word)
  49
  50 -- Operators.
  51 local operator = token(l.OPERATOR, S('=><+-*^&:.,_()'))
  52
  53 M._rules = {
  54   {'whitespace', ws},
  55   {'keyword', keyword},
  56   {'type', type},
  57   {'comment', comment},
  58   {'identifier', identifier},
  59   {'string', string},
  60   {'number', number},
  61   {'operator', operator},
  62 }
  63
  64 return M