2007-07-14 10:21:22 -04:00
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2007/07/14:
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2007-07-11 06:34:22 -04:00
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2007-07-14 10:21:22 -04:00
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The rules are currently confusingly implemented, and have poor performance when
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used in deeply nested grammars.
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2007-07-11 06:34:22 -04:00
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2007-07-14 10:21:22 -04:00
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We need to refactor lex2 so that rules have two methods:
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1. match():
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This method should return whether or not the rule can match the current input
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that the lexer is lexing. If its result is true, the result will be passed
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(along with the lexer, etc.) to the rule's lex() method. Otherwise, the next
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rule will be tried.
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2. lex():
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This method is a generator, which is expected to return one or more tokens. In
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addition to the arguments given to match() it will be passed the result of the
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call to match() (which is guaranteed to be true, and will most often be a
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re.Match object). As all generators, this method will raise StopIteration when
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there are no more tokens to return, and will raise LexError if there are other
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problems.
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