52 lines
1.6 KiB
Lua
Executable File
52 lines
1.6 KiB
Lua
Executable File
-- Copyright 2006-2019 Mitchell mitchell.att.foicica.com. See License.txt.
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-- Io LPeg lexer.
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local lexer = require('lexer')
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local token, word_match = lexer.token, lexer.word_match
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local P, R, S = lpeg.P, lpeg.R, lpeg.S
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local lex = lexer.new('io_lang')
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-- Whitespace.
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lex:add_rule('whitespace', token(lexer.WHITESPACE, lexer.space^1))
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-- Keywords.
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lex:add_rule('keyword', token(lexer.KEYWORD, word_match[[
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block method while foreach if else do super self clone proto setSlot hasSlot
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type write print forward
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]]))
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-- Types.
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lex:add_rule('type', token(lexer.TYPE, word_match[[
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Block Buffer CFunction Date Duration File Future LinkedList List Map Message
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Nil Nop Number Object String WeakLink
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]]))
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-- Identifiers.
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lex:add_rule('identifier', token(lexer.IDENTIFIER, lexer.word))
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-- Strings.
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local sq_str = lexer.delimited_range("'")
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local dq_str = lexer.delimited_range('"')
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local tq_str = '"""' * (lexer.any - '"""')^0 * P('"""')^-1
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lex:add_rule('string', token(lexer.STRING, tq_str + sq_str + dq_str))
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-- Comments.
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local line_comment = (P('#') + '//') * lexer.nonnewline^0
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local block_comment = '/*' * (lexer.any - '*/')^0 * P('*/')^-1
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lex:add_rule('comment', token(lexer.COMMENT, line_comment + block_comment))
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-- Numbers.
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lex:add_rule('number', token(lexer.NUMBER, lexer.float + lexer.integer))
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-- Operators.
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lex:add_rule('operator', token(lexer.OPERATOR,
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S('`~@$%^&*-+/=\\<>?.,:;()[]{}')))
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-- Fold points.
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lex:add_fold_point(lexer.OPERATOR, '(', ')')
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lex:add_fold_point(lexer.COMMENT, '/*', '*/')
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lex:add_fold_point(lexer.COMMENT, '//', lexer.fold_line_comments('//'))
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return lex
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