Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!samsung!think!snorkelwacker!mit-eddie!rutgers!psuvax1!psuvm!cmh117
From: CMH117@psuvm.psu.edu (Charles Hannum)
Newsgroups: comp.lang.c
Subject: Re: Wanted: Expression Evaluator
Message-ID: <90052.234131CMH117@psuvm.psu.edu>
Date: 22 Feb 90 04:41:31 GMT
References: <4365@jarthur.Claremont.EDU>
 <1990Feb19.012607.22402@ux1.cso.uiuc.edu>
Organization: Penn State University
Lines: 26


>In article <4365@jarthur.Claremont.EDU> ssdken@jarthur.Claremont.EDU (Ken
>Nelson) writes:
>>Hi:
>>
>>   I need the C source for an expression evaluator. Something that can
>>   understand things like this:
>>
>>      A/B*LOG(D)
>>
>>
>>   The evaluator would get A B and D from a symbol table, evaluate the
>>   expression and return the result.
>>
>>   Anybody have such a beast????

I have an O(n) parser that I think will do what you want.  It uses a stack-
based algorithm which I invented and later discovered that I was not the first
to do so ...  <sigh>


Virtually,
- Charles Martin Hannum II       "Klein bottle for sale ... inquire within."
    (That's Charles to you!)     "To life immortal!"
  cmh117@psuvm.{bitnet,psu.edu}  "No noozzzz izzz netzzzsnoozzzzz..."
  c9h@psuecl.{bitnet,psu.edu}    "Mem'ry, all alone in the moonlight ..."