vis

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

(1538B)
      1 -- Copyright 2006-2025 Mitchell. See LICENSE.
      2 -- Io 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('io_lang')
      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 	'block', 'method', 'while', 'foreach', 'if', 'else', 'do', 'super', 'self', 'clone', 'proto',
     16 	'setSlot', 'hasSlot', 'type', 'write', 'print', 'forward'
     17 }))
     18 
     19 -- Types.
     20 lex:add_rule('type', token(lexer.TYPE, word_match{
     21 	'Block', 'Buffer', 'CFunction', 'Date', 'Duration', 'File', 'Future', 'LinkedList', 'List', 'Map',
     22 	'Message', 'Nil', 'Nop', 'Number', 'Object', 'String', 'WeakLink'
     23 }))
     24 
     25 -- Identifiers.
     26 lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word))
     27 
     28 -- Strings.
     29 local sq_str = lexer.range("'")
     30 local dq_str = lexer.range('"')
     31 local tq_str = lexer.range('"""')
     32 lex:add_rule('string', token(lexer.STRING, tq_str + sq_str + dq_str))
     33 
     34 -- Comments.
     35 local line_comment = lexer.to_eol(P('#') + '//')
     36 local block_comment = lexer.range('/*', '*/')
     37 lex:add_rule('comment', token(lexer.COMMENT, line_comment + block_comment))
     38 
     39 -- Numbers.
     40 lex:add_rule('number', token(lexer.NUMBER, lexer.number))
     41 
     42 -- Operators.
     43 lex:add_rule('operator', token(lexer.OPERATOR, S('`~@$%^&*-+/=\\<>?.,:;()[]{}')))
     44 
     45 -- Fold points.
     46 lex:add_fold_point(lexer.OPERATOR, '(', ')')
     47 lex:add_fold_point(lexer.COMMENT, '/*', '*/')
     48 
     49 lexer.property['scintillua.comment'] = '#'
     50 
     51 return lex