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[Chicken-users] Question about the greediness of the lexgen egg's lex pr


From: Sam Hardwick
Subject: [Chicken-users] Question about the greediness of the lexgen egg's lex procedure
Date: Mon, 22 Oct 2012 15:32:15 +0300
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.9) Gecko/20121014 Icedove/10.0.9

If I'm understanding things correctly, the lexgen egg's lex procedure is (at least in some cases) matching based of the order of specification (match the first possible thing), not on longest possible match. Can this be right? The documentation says

"lex takes a pattern and a string, turns the string into a list of streams (containing one stream), applies the pattern, and returns the longest match."

I placed an example of what I mean at http://paste.call-cc.org/paste?id=8196b316bf50c18bb044870f95bbbebb00e5026d . Here, testpat1 will match "..." as one "." followed by an untokenizable remainder, whereas testpat2 will match "..." correctly in its entirety.

Sam Hardwick



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