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GenLex stream parsers too eager?
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Date: -- (:)
From: David McClain <dmcclain@a...>
Subject: GenLex stream parsers too eager?
It appears that the Genlex derived parsers always eagerly tokenize =
negaitve integer and float constants. This causes incorrect behavior in =
closely spaced code (no-spaces):

    a-2*c  --> parses as  "a", "-2" ,"*", "c"  instead of =
"a","-","2","*","c"

So instead of getting one expression tree, I get two, with the first =
containing only "a".
Also, if the operator were exponentiation instead of multiplication, the =
second tree would incorrectly compute a (possibly) complex valued =
expression instead of a simple negative of a real expression.

I have tried various workarounds, but they really obfuscate the original =
recursive descent structure of parsers.

Any suggestions? (Perhaps I should be using OCAMLLEX and OCAMLYACC =
instead?)

David McClain
Sr. Scientist
Raytheon Missile Systems Co.
Tucson, AZ
http://www.azstarnet.com/~dmcclain/homepage.htm