Re: change ni * protos

[Gurusamy Sarathy <gsar@ActiveState.com>]

On Fri, 21 Jan 2000 16:48:26 MST, Tom Christiansen wrote:
>Could you please remind me why you intentionally broke
>
>    use strict;
>    sub fn(*) { my $fh = shift;  print $fh "Boo!\n" }
>    *SNEAK = *STDOUT;
>    fn(SNEAK);

Did you see:

  http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/1999-04/msg00312.html

The long and the short of it is that the current semantics make it
possible to override builtins like open() and require(), which need to
see simple scalar values as they were passed, not as typeglobs.  When
you see the "*" prototype, think "any scalar including bareword" rather
than "typeglob".

>#########################
># This file:
>#########################
>
>    use strict;
>
>    $|=1; 
>
>    package Fab;
>
>    sub ululation(*) { 
>	my $fh = shift;

Replace that with:

        use Symbol 'qualify_to_ref';
	my $fh = qualify_to_ref(shift,caller);

>	print $fh "this went out $fh\n"
>	    or warn "failed to print to fh $fh: $!\n";
>
>    } 
>
>    package main;
>
>    print "testing *STDOUT...."; Fab::ululation(*STDOUT);
>    print "testing *stdout...."; Fab::ululation(*stdout);
>
>    print "testing *STDOUT{IO}...."; Fab::ululation(*STDOUT{IO});
>    print "testing *stdout{IO}...."; Fab::ululation(*stdout{IO});
>
>    print "testing STDOUT...."; Fab::ululation(STDOUT);
>    print "testing stdout...."; Fab::ululation(stdout);
>
>    print "testing *snigglebottom...."; Fab::ululation(*snigglebottom);
>    print "testing *snigglebottom{IO}...."; Fab::ululation(*snigglebottom{IO});
>    print "testing snigglebottom...."; Fab::ululation(snigglebottom);
>
>    __END__


Sarathy
gsar@ActiveState.com

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Follow-Ups from:

Gurusamy Sarathy <gsar@ActiveState.com>
Tim Bunce <Tim.Bunce@ig.co.uk>

References to:

Tom Christiansen <tchrist@chthon.perl.com>

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