Path: utzoo!mnetor!tmsoft!torsqnt!hybrid!scifi!bywater!uunet!convex!news
From: tchrist@convex.COM (Tom Christiansen)
Newsgroups: comp.lang.perl
Subject: Re: Do be do be do.
Message-ID: <1991Feb04.125401.29075@convex.com>
Date: 4 Feb 91 12:54:01 GMT
References: <121266@uunet.UU.NET> <1991Feb04.034645.3658@convex.com> <121307@uunet.UU.NET>
Sender: news@convex.com (news access account)
Reply-To: tchrist@convex.COM (Tom Christiansen)
Organization: CONVEX Software Development, Richardson, TX
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From the keyboard of rbj@uunet.UU.NET (Root Boy Jim):
:[Tom explains diff between "do sub;" != "do sub()" == "&sub()" != "&sub"

    do sub;

is illegal.  you need the parens.

:	function(a,r,g,s) while condition
:with
:	&Function(a,r,g,s) while condition
:
:I see no reason to treat a subroutine call different from any
:other expression. This is counterintuitive. 

I hope I haven't led you to believe that it is different.
In both cases, the while gets evaluated first; that's just
how statement modifiers work.  Only for 
    do { FOO } while EXPR;
should the loop execute at least once (FORTRAN 66 mode :-) irrespective
of the EXPR's value.  because the while is NOT evaluated until the end,
Otherwise people would be surprised.

So these will not happen:
    &FOO while 0;
    do FOO() while 0;
but this will:
    do { &FOO; } while 0;

--tom
--
"Still waiting to read alt.fan.dan-bernstein using DBWM, Dan's own AI
window manager, which argues with you 10 weeks before resizing your window." 
### And now for the question of the month:  How do you spell relief?   Answer:
U=brnstnd@kramden.acf.nyu.edu; echo "/From: $U/h:j" >>~/News/KILL; expire -f $U