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----- Original Message -----
From: "Johnathan Kupferer" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, April 30, 2001 5:38 PM
Subject: Re: FileCache - use strict
> This one got under my skin so I did a little research:
>
> > use strict;
> > use FileCache;
> > my $a01;
> > $a01 = 'a01file';
> > cacheout $a01;
> > print $a01 "XYZ\n";
>
> It seems that perl decides that its calling print with arguments '$a01
> "XYZ\n"' and then chokes on the argument list. Turns out that this is one
> of those ambiguites of Perl's indirect object syntax. It caught me off
> gaurd that cacheout $a01 turns a string into a file handle, I can't say
that
> I condone such things, but nobody asked me. Since $a01 is a file handle,
we
> can avoid using the indirect syntax by calling its print method:
>
> use strict;
> use IO::FileHandle;
> use FileCache;
> my $a01;
> $a01 = 'a01file';
> cacheout $a01;
> $a01->print("XYZ\n");
>
> Notice that I had to add "use IO::FileHandle". This is another curiosity,
> why am I able to create IO::FileHandle objects when IO::FileHandle was not
> accessable?
>
> I know the technical answer is that Perl gives me the freedom to create
any
> kind of object I want. For example with "bless($myself, 'unicorn')" I can
> turn $myself into a 'unicorn'. But in what sense can I consider $myself a
> 'unicorn' if I have no access to a package called 'unicorn' from which I
may
> access my methods. Maybe I shouldn't be able to turn into a 'unicorn'
> unless I know what a 'unicorn' is. Does anyone know of a way to catch
such
> things.
>
> It seems that "use FileCache" should imply "use IO::FileHandle" if it is
> creating such objects. I guess what really disturbs me is that Perl isn't
> playing by the rules by only considering file handles objects in a half
> hearted sort of way. Why bother blessing them at all if behind the seens
it
> runs open, print, close etc without consulting the IO::FileHandle modules?
>
> This seems to answer a question I had a while back. Why does Perl bother
> with the tie function if you can create a new object that responds to all
> the methods of a file. I think it has something to do with calling things
> like:
>
> print $pseudo_file "stuff"
>
> would run into the same problem above and not translate to:
>
> $pseudo_file->print("stuff");
>
> Like
>
> $pseudo_file = new PseudoFile;
>
> translates to:
>
> $pseudo_file = PseudoFile->new();
>
> All I can say is I hope that we see stuff like this get cleaned up in Perl
> 6. Anyway, the above code does work and its kinda cleaner than the
indirect
> syntax anyway.
>
> - Johnathan
>
>
>
