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From: achrist@easystreet.com
Newsgroups: comp.lang.ada
Subject: Re: FAQ and string functions
Date: Fri, 02 Aug 2002 22:07:34 -0700
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Date: 2002-08-02T22:07:34-07:00
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Ted Dennison wrote:
> 
> no problem at all if you program everthing functionally.
> 

Just a few weeks ago I wrote an Ada program that does lots of string
splitting and concatenation, and I wrote it functionally, and it
runs very slowly.  Things like extracting the nth item in a string 
by extracting the 1st item n times and all that, all recursively. 

I'm guessing that some of the performance problem is related to Ada
not being a functional language and that if you want to write 
functional programs, Ada is not the best choice.  I'm not sure, 
just guessing.  

Is that true?  Does a typical Ada compiler, for example GNAT 3.14
public edition that I used, have optimizations for tail-recursive
functions?  Or will I get into trouble if I over-abuse recursion
in Ada?  For example, if I was recursively splitting a string 
of 100 kb into 1,000 pieces, might I eat up 100 Meg of stack or
even crash?  As I understand it, compilers for functional languages
generate code so that programs that are written functionally with 
proper tail recursion run pretty much as efficiently as they would 
if they were written loopishly.   That won't happen with Ada, will 
it?


Al