lexers/xtend.lua

   1 -- Copyright (c) 2014-2015 Piotr Orzechowski [drzewo.org]. See LICENSE.
   2 -- Xtend 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 = 'xtend'}
   9
  10 -- Whitespace.
  11 local ws = token(l.WHITESPACE, l.space^1)
  12
  13 -- Comments.
  14 local line_comment = '//' * l.nonnewline_esc^0
  15 local block_comment = '/*' * (l.any - '*/')^0 * P('*/')^-1
  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 string = token(l.STRING, sq_str + dq_str)
  22
  23 -- Templates.
  24 local templ_str = "'''" * (l.any - P("'''"))^0 * P("'''")^-1
  25 local template = token('template', templ_str, true)
  26
  27 -- Numbers.
  28 local small_suff = S('lL')
  29 local med_suff = P(S('bB') * S('iI'))
  30 local large_suff = S('dD') + S('fF') + P(S('bB') * S('dD'))
  31 local exp = S('eE') * l.digit^1
  32
  33 local dec_inf = ('_' * l.digit^1)^0
  34 local hex_inf = ('_' * l.xdigit^1)^0
  35 local float_pref = l.digit^1 * '.' * l.digit^1
  36 local float_suff = exp^-1 * med_suff^-1 * large_suff^-1
  37
  38 local dec = l.digit * dec_inf * (small_suff^-1 + float_suff)
  39 local hex = l.hex_num * hex_inf * P('#' * (small_suff + med_suff))^-1
  40 local float = float_pref * dec_inf * float_suff
  41
  42 local number = token(l.NUMBER, float + hex + dec)
  43
  44 -- Keywords.
  45 local keyword = token(l.KEYWORD, word_match{
  46   -- General.
  47   'abstract', 'annotation', 'as', 'case', 'catch', 'class', 'create', 'def',
  48   'default', 'dispatch', 'do', 'else', 'enum', 'extends', 'extension', 'final',
  49   'finally', 'for', 'if', 'implements', 'import', 'interface', 'instanceof',
  50   'it', 'new', 'override', 'package', 'private', 'protected', 'public',
  51   'return', 'self', 'static', 'super', 'switch', 'synchronized', 'this',
  52   'throw', 'throws', 'try', 'typeof', 'val', 'var', 'while',
  53   -- Templates.
  54   -- 'AFTER', 'BEFORE', 'ENDFOR', 'ENDIF', 'FOR', 'IF', 'SEPARATOR',
  55   -- Literals.
  56   'true', 'false', 'null'
  57 })
  58
  59 -- Types.
  60 local type = token(l.TYPE, word_match{
  61   'boolean', 'byte', 'char', 'double', 'float', 'int', 'long', 'short', 'void',
  62   'Boolean', 'Byte', 'Character', 'Double', 'Float', 'Integer', 'Long', 'Short',
  63   'String'
  64 })
  65
  66 -- Identifiers.
  67 local identifier = token(l.IDENTIFIER, l.word)
  68
  69 -- Operators.
  70 local operator = token(l.OPERATOR, S('+-/*%<>!=^&|?~:;.()[]{}#'))
  71
  72 -- Annotations.
  73 local annotation = token('annotation', '@' * l.word)
  74
  75 -- Functions.
  76 local func = token(l.FUNCTION, l.word) * #P('(')
  77
  78 -- Classes.
  79 local class = token(l.KEYWORD, P('class')) * ws^1 * token(l.CLASS, l.word)
  80
  81 -- Rules.
  82 M._rules = {
  83   {'whitespace', ws},
  84   {'class', class},
  85   {'keyword', keyword},
  86   {'type', type},
  87   {'function', func},
  88   {'identifier', identifier},
  89   {'template', template},
  90   {'string', string},
  91   {'comment', comment},
  92   {'number', number},
  93   {'annotation', annotation},
  94   {'operator', operator},
  95   {'error', token(l.ERROR, l.any)},
  96 }
  97
  98 -- Token styles.
  99 M._tokenstyles = {
 100   annotation = l.STYLE_PREPROCESSOR,
 101   template = l.STYLE_EMBEDDED
 102 }
 103
 104 -- Folding.
 105 M._foldsymbols = {
 106   _patterns = {'[{}]', '/%*', '%*/', '//', 'import'},
 107   [l.OPERATOR] = {['{'] = 1, ['}'] = -1},
 108   [l.COMMENT] = {['/*'] = 1, ['*/'] = -1, ['//'] = l.fold_line_comments('//')},
 109   [l.KEYWORD] = {['import'] = l.fold_line_comments('import')}
 110 }
 111
 112 return M