vis

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

(2195B)
      1 -- Copyright 2006-2025 Mitchell. See LICENSE.
      2 -- Eiffel 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('eiffel')
      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 	'alias', 'all', 'and', 'as', 'check', 'class', 'creation', 'debug', 'deferred', 'do', 'else',
     16 	'elseif', 'end', 'ensure', 'expanded', 'export', 'external', 'feature', 'from', 'frozen', 'if',
     17 	'implies', 'indexing', 'infix', 'inherit', 'inspect', 'invariant', 'is', 'like', 'local', 'loop',
     18 	'not', 'obsolete', 'old', 'once', 'or', 'prefix', 'redefine', 'rename', 'require', 'rescue',
     19 	'retry', 'select', 'separate', 'then', 'undefine', 'until', 'variant', 'when', 'xor', --
     20 	'current', 'false', 'precursor', 'result', 'strip', 'true', 'unique', 'void'
     21 }))
     22 
     23 -- Types.
     24 lex:add_rule('type',
     25 	token(lexer.TYPE, word_match('character string bit boolean integer real none any')))
     26 
     27 -- Identifiers.
     28 lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word))
     29 
     30 -- Strings.
     31 local sq_str = lexer.range("'", true)
     32 local dq_str = lexer.range('"', true)
     33 lex:add_rule('string', token(lexer.STRING, sq_str + dq_str))
     34 
     35 -- Comments.
     36 lex:add_rule('comment', token(lexer.COMMENT, lexer.to_eol('--')))
     37 
     38 -- Numbers.
     39 lex:add_rule('number', token(lexer.NUMBER, lexer.number))
     40 
     41 -- Operators.
     42 lex:add_rule('operator', token(lexer.OPERATOR, S('=!<>+-/*%&|^~.,:;?()[]{}')))
     43 
     44 -- Fold points.
     45 lex:add_fold_point(lexer.KEYWORD, 'check', 'end')
     46 lex:add_fold_point(lexer.KEYWORD, 'debug', 'end')
     47 lex:add_fold_point(lexer.KEYWORD, 'deferred',
     48 	function(text, pos, line, s) return line:find('deferred%s+class') and 0 or 1 end)
     49 lex:add_fold_point(lexer.KEYWORD, 'do', 'end')
     50 lex:add_fold_point(lexer.KEYWORD, 'from', 'end')
     51 lex:add_fold_point(lexer.KEYWORD, 'if', 'end')
     52 lex:add_fold_point(lexer.KEYWORD, 'inspect', 'end')
     53 lex:add_fold_point(lexer.KEYWORD, 'once', 'end')
     54 lex:add_fold_point(lexer.KEYWORD, 'class',
     55 	function(text, pos, line, s) return line:find('deferred%s+class') and 0 or 1 end)
     56 
     57 lexer.property['scintillua.comment'] = '--'
     58 
     59 return lex