39 lines
1.0 KiB
Plaintext
Executable File
39 lines
1.0 KiB
Plaintext
Executable File
-- ? 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('?')
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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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keyword1 keyword2 keyword3
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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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lex:add_rule('string', token(lexer.STRING, lexer.delimited_range("'") +
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lexer.delimited_range('"')))
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-- Comments.
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lex:add_rule('comment', token(lexer.COMMENT, '#' * lexer.nonnewline^0))
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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, S('+-*/%^=<>,.{}[]()')))
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-- Fold points.
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lex:add_fold_point(lexer.KEYWORD, 'start', 'end')
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lex:add_fold_point(lexer.OPERATOR, '{', '}')
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lex:add_fold_point(lexer.COMMENT, '#', lexer.fold_line_comments('#'))
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return lex
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