Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sdd.hp.com!hplabs!hpl-opus!hpnmdla!chrise
From: chrise@hpnmdla.hp.com (Chris Eich)
Newsgroups: comp.lang.perl
Subject: Re: Which to use :- Perl, Python, Icon, ... ?
Message-ID: <8310023@hpnmdla.hp.com>
Date: 6 Mar 91 22:13:58 GMT
References: <BEVAN.91Mar5123224@tiger.cs.man.ac.uk>
Organization: HP Network Measurements Div, Santa Rosa, CA
Lines: 39


  + Does the language have any arbitrary limits? e.g. the length of a
    line ... etc.

The perl man page says:

    While none of the built-in data types have any arbitrary size limits
    (apart from memory size), there are still a few arbitrary limits: a
    given identifier may not be longer than 255 characters; sprintf is
    limited on many machines to 128 characters per field (unless the
    format specifier is exactly %s); and no component of your PATH may
    be longer than 255 if you use -S.

There is another limit (due to the use of yacc):  expression complexity.

On my HP-UX 7.0 system (3.044 perl), the following code:

    $Expr = '(1)';
    while (eval '$Val = ' . $Expr) {
	print $Val, "\n";
	$Expr = '(' . $Expr . '+1)';
    }
    print $@, "\n";

demonstrates that limit like so:

    1
    2
    3
    ...
    140
    141
    142
    yacc stack overflow in file (eval) at line 1, next 2 tokens "1)"

I ran into this today while trying to get around the exact same problem
in bc(1)!  Larry, is this worth a mention on the man page?

Chris