vis

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

(1341B)
      1 -- Copyright 2006-2025 Mitchell. See LICENSE.
      2 -- Gap 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('gap')
      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 	'and', 'break', 'continue', 'do', 'elif', 'else', 'end', 'fail', 'false', 'fi', 'for', 'function',
     16 	'if', 'in', 'infinity', 'local', 'not', 'od', 'or', 'rec', 'repeat', 'return', 'then', 'true',
     17 	'until', 'while'
     18 }))
     19 
     20 -- Identifiers.
     21 lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word))
     22 
     23 -- Strings.
     24 local sq_str = lexer.range("'", true)
     25 local dq_str = lexer.range('"', true)
     26 lex:add_rule('string', token(lexer.STRING, sq_str + dq_str))
     27 
     28 -- Comments.
     29 lex:add_rule('comment', token(lexer.COMMENT, lexer.to_eol('#')))
     30 
     31 -- Numbers.
     32 lex:add_rule('number', token(lexer.NUMBER, lexer.dec_num * -lexer.alpha))
     33 
     34 -- Operators.
     35 lex:add_rule('operator', token(lexer.OPERATOR, S('*+-,./:;<=>~^#()[]{}')))
     36 
     37 -- Fold points.
     38 lex:add_fold_point(lexer.KEYWORD, 'function', 'end')
     39 lex:add_fold_point(lexer.KEYWORD, 'do', 'od')
     40 lex:add_fold_point(lexer.KEYWORD, 'if', 'fi')
     41 lex:add_fold_point(lexer.KEYWORD, 'repeat', 'until')
     42 
     43 lexer.property['scintillua.comment'] = '#'
     44 
     45 return lex