vis

a vi-like editor based on Plan 9's structural regular expressions
antlr.lua

(1913B)
      1 -- Copyright 2006-2025 Mitchell. See LICENSE.
      2 -- ANTLR LPeg lexer.
      3 
      4 local lexer = require('lexer')
      5 local token, word_match = lexer.token, lexer.word_match
      6 local P, S = lpeg.P, lpeg.S
      7 
      8 local lex = lexer.new('antlr')
      9 
     10 -- Whitespace.
     11 lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))
     12 
     13 -- Keywords.
     14 lex:add_rule('keyword', token(lexer.KEYWORD, word_match{
     15 	'abstract', 'break', 'case', 'catch', 'continue', 'default', 'do', 'else', 'extends', 'final',
     16 	'finally', 'for', 'if', 'implements', 'instanceof', 'native', 'new', 'private', 'protected',
     17 	'public', 'return', 'static', 'switch', 'synchronized', 'throw', 'throws', 'transient', 'try',
     18 	'volatile', 'while', 'package', 'import', 'header', 'options', 'tokens', 'strictfp', 'false',
     19 	'null', 'super', 'this', 'true'
     20 }))
     21 
     22 -- Types.
     23 lex:add_rule('type', token(lexer.TYPE, word_match(
     24 	'boolean byte char class double float int interface long short void')))
     25 
     26 -- Functions.
     27 lex:add_rule('func', token(lexer.FUNCTION, 'assert'))
     28 
     29 -- Identifiers.
     30 lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word))
     31 
     32 -- Comments.
     33 local line_comment = lexer.to_eol('//')
     34 local block_comment = lexer.range('/*', '*/')
     35 lex:add_rule('comment', token(lexer.COMMENT, line_comment + block_comment))
     36 
     37 -- Actions.
     38 local open_brace = token(lexer.OPERATOR, '{')
     39 local close_brace = token(lexer.OPERATOR, '}')
     40 lex:add_rule('action', open_brace * token('action', (1 - P('}'))^0) * close_brace^-1)
     41 lex:add_style('action', lexer.styles.nothing)
     42 
     43 -- Strings.
     44 lex:add_rule('string', token(lexer.STRING, lexer.range("'", true)))
     45 
     46 -- Operators.
     47 lex:add_rule('operator', token(lexer.OPERATOR, S('$@:;|.=+*?~!^>-()[]{}')))
     48 
     49 -- Fold points.
     50 lex:add_fold_point(lexer.OPERATOR, ':', ';')
     51 lex:add_fold_point(lexer.OPERATOR, '(', ')')
     52 lex:add_fold_point(lexer.OPERATOR, '{', '}')
     53 lex:add_fold_point(lexer.COMMENT, '/*', '*/')
     54 
     55 lexer.property['scintillua.comment'] = '//'
     56 
     57 return lex