lua/lexers/go.lua

   1 -- Copyright 2006-2017 Mitchell mitchell.att.foicica.com. See LICENSE.
   2 -- Go 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 = 'go'}
   9
  10 -- Whitespace.
  11 local ws = token(l.WHITESPACE, l.space^1)
  12
  13 -- Comments.
  14 local line_comment = '//' * l.nonnewline^0
  15 local block_comment = '/*' * (l.any - '*/')^0 * '*/'
  16 local comment = token(l.COMMENT, line_comment + block_comment)
  17
  18 -- Strings.
  19 local sq_str = l.delimited_range("'", true)
  20 local dq_str = l.delimited_range('"', true)
  21 local raw_str = l.delimited_range('`', false, true)
  22 local string = token(l.STRING, sq_str + dq_str + raw_str)
  23
  24 -- Numbers.
  25 local number = token(l.NUMBER, (l.float + l.integer) * P('i')^-1)
  26
  27 -- Keywords.
  28 local keyword = token(l.KEYWORD, word_match{
  29   'break', 'case', 'chan', 'const', 'continue', 'default', 'defer', 'else',
  30   'fallthrough', 'for', 'func', 'go', 'goto', 'if', 'import', 'interface',
  31   'map', 'package', 'range', 'return', 'select', 'struct', 'switch', 'type',
  32   'var'
  33 })
  34
  35 -- Constants.
  36 local constant = token(l.CONSTANT, word_match{
  37   'true', 'false', 'iota', 'nil'
  38 })
  39
  40 -- Types.
  41 local type = token(l.TYPE, word_match{
  42   'bool', 'byte', 'complex64', 'complex128', 'error', 'float32', 'float64',
  43   'int', 'int8', 'int16', 'int32', 'int64', 'rune', 'string', 'uint', 'uint8',
  44   'uint16', 'uint32', 'uint64', 'uintptr'
  45 })
  46
  47 -- Functions.
  48 local func = token(l.FUNCTION, word_match{
  49   'append', 'cap', 'close', 'complex', 'copy', 'delete', 'imag', 'len', 'make',
  50   'new', 'panic', 'print', 'println', 'real', 'recover'
  51 })
  52
  53 -- Identifiers.
  54 local identifier = token(l.IDENTIFIER, l.word)
  55
  56 -- Operators.
  57 local operator = token(l.OPERATOR, S('+-*/%&|^<>=!:;.,()[]{}'))
  58
  59 M._rules = {
  60   {'whitespace', ws},
  61   {'keyword', keyword},
  62   {'constant', constant},
  63   {'type', type},
  64   {'function', func},
  65   {'identifier', identifier},
  66   {'string', string},
  67   {'comment', comment},
  68   {'number', number},
  69   {'operator', operator},
  70 }
  71
  72 M._foldsymbols = {
  73   _patterns = {'[{}]', '/%*', '%*/', '//'},
  74   [l.OPERATOR] = {['{'] = 1, ['}'] = -1},
  75   [l.COMMENT] = {['/*'] = 1, ['*/'] = -1, ['//'] = l.fold_line_comments('//')}
  76 }
  77
  78 return M