[antlr-interest] comparing two parse trees

[Loring Craymer]

This involves algebraic rewrites; you want to extend an algebraic normal form 
(see wikipedia article) to include exponentiation and express division in terms 
of negative exponents and compare formulae after conversion to normal form.  And 
you probably want to do constant folding (another wikipedia article) while you 
are at it.

--Loring



----- Original Message ----
> From: Jon Svede <jsvede at yahoo.com>
> To: antlr-interest at antlr.org
> Sent: Tue, September 14, 2010 12:29:28 PM
> Subject: [antlr-interest] comparing two parse trees
> 
> Hi,
> 
> I am new to ANTLR.
> 
> I want to be able to compare formulas to  see if the are the same formula, 
>something like the following:
> 
> (A + B /  C)^D
> 
> Compared to
> 
> (W+X)/Y^Z
> 
> I don't particularly care about  the actual terms of the equations (well, not 
>right now anyway), I just want to  know if they are structurally the same.
> 
> Can anyone point me in the right  direction as far as docs that talk about 
>this? Is this covered in the book "The  Definitive Guide to ANTLR"?  I don't 
>recall reading anything about this(or  maybe I missed it?)...
> 
> Thanks in advance for any  assistance!
> 
> Sincerely,
> 
> Jon
> 
> 
> 
>       
> 
> 
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