Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!tut.cis.ohio-state.edu!usenet.ins.cwru.edu!ncoast!allbery
From: allbery@NCoast.ORG (Brandon S. Allbery KB8JRR)
Newsgroups: comp.lang.perl
Subject: Re: While learning PERL... a suggestion
Message-ID: <1991Jan22.012359.24492@NCoast.ORG>
Date: 22 Jan 91 01:23:59 GMT
References: <1991Jan21.092204.11944@ux1.cso.uiuc.edu> <1991Jan21.174520.12207@iwarp.intel.com> <1991Jan21.201845.28080@ux1.cso.uiuc.edu>
Reply-To: allbery@ncoast.ORG (Brandon S. Allbery KB8JRR)
Followup-To: comp.lang.perl
Organization: North Coast Computer Resources (ncoast)
Lines: 44

As quoted from <1991Jan21.201845.28080@ux1.cso.uiuc.edu> by phil@ux1.cso.uiuc.edu (Phil Howard KA9WGN):
+---------------
| My only comment is that this must be a very complex syntax to parse.
| The mere existance of space between the handle and the string above
| would separate things.  I wonder if there are any cases where the
| data to be printed could be an expression with a unary prefix operator
| that could cause an apparent ambiguity as to look like a binary infix
| operator between the filehandle and the data, thus appearing to be an
| expression to be printed on STDOUT.
+---------------

I don't know what Perl does in that case (Perl isn't installed on ncoast), but
there is a disambiguator:  the full syntax of "print" is:

	print FILEHANDLE [(] arguments [)];

Just enclose the arguments to be printed in parentheses.  The ambiguity is no
different from the usual Perl irregularity, where operators like "print",
"chmod", and just about everything else take a following left parenthesis as
an argument indicator a' la C functions.  You just have to be careful.

+---------------
| In what way does it affect them?  I was getting the impression from the
| man pages that these name spaces were separate.  This was discussed in
| the man pages with regard to passing by references, but I guess you are
| now filling in the ambiguities of its affect elswhere.  I'm not up on
| subroutines yet (probably mostly due to not understand how the name
| space works).
+---------------

The problem is that the * syntax doesn't support specifying *which* namespace
to alter:  does "*x" refer to a filehandle, a scalar, an array, or an
associative array?  And you can't say "*$a" to specify which (not that it
would help anyway, since filehandles don't have indicators and you would need
to retain the current behavior of "*x" for compatibility.

This can be viewed as a drawback of Perl, or of * indirection.

++Brandon
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