Hi, I don't know much about the parser tools, so I can't help you on that. But I recently made a simple quick-and-dirty text parser tool: <a href="http://planet.plt-scheme.org/package-source/orseau/lazy-doc.plt/1/6/planet-docs/manual/simple-parser.html">http://planet.plt-scheme.org/package-source/orseau/lazy-doc.plt/1/6/planet-docs/manual/simple-parser.html</a> It does not make any difference between lexing and parsing, so you can mix both easily. It can also be controlled dynamically so you should be able to modify the separator on the fly. If you're interested I can provide some more help. For larger applications than quick-and-dirty, I would certainly recommend the integrated parsing tools, though. Although if all you need is separate data with a given string, then using a lexer and a parser might be a bit overkill... Maybe using just regexp-split would be enough. Laurent <div class="gmail_quote">2009/11/7 Ivanyi Peter <<a href="mailto:pivanyi@freemail.hu">pivanyi@freemail.hu</a>> <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> Hi, Is it possible to create a lexer and parser dynamically? I would like to create an application, which, for example, reads in a file which contains what the separator character is and after that the program can read in another file, but considers the separator character. Somehow I could not manage to create a variable, which then can be used in a lexer. Any way to do this? Thanks for any help. Best regards, Peter Ivanyi _________________________________________________ For list-related administrative tasks: <a href="http://list.cs.brown.edu/mailman/listinfo/plt-scheme" target="_blank">http://list.cs.brown.edu/mailman/listinfo/plt-scheme</a> </blockquote></div>