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using different lexers with one parser?
- Oliver Bandel
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Date: | 2007-04-17 (20:33) |
From: | Oliver Bandel <oliver@f...> |
Subject: | using different lexers with one parser? |
Hello, using many parsers with ocamlyacc is possible, because ocamlyacc provides the possibility forusing moire than one start-token. Using many lexers is possible with ocamllex, because each lexer is a seperated function. Is it possible (without too much effort) to switch the lexer during parsing (from within the parser)? Or is better to a) implement calling of different lexers in the *.mll file or b) use many starting-points of the *.mly-file and work on the data from the outside of the parser (I'm meaning here: the function that calls the yacc-grammar-rule (start-rule)? So: does it rather make sense to make a higher-level parse on the data that the *.mly-parser gives back?! BTW: The data (line-based) I want to parse could otherwise be parsed relatively easy with regexp's; maybe this is the better way? Or is there a way to convert such context-dependend things to ocamllex/ocamlyacc-syntaxes? (It seems to me that similar problems arise, when parsing files like picture-files or movie-files (mpg or so).) TIA, Oliver