Chaim Frenkel wrote:
> >>>>> "JE" == Jon Ericson <[EMAIL PROTECTED]> writes:
> JE> $gaz contains the second line. Otherwise this:
>
> JE> while (<'filename'>){print;};
>
> JE> won't work. This gets a little hairy, I admit.
>
> Actually they are two different problems. The while loop can be
> internally replaced with an open, while, close. Or with a local
> version of a filehandle that _only_ is valid at that line or
> block.
Sometimes I do this:
<'somefile'>; # I don't care about the first line
while (<'somefile'>){
# do something with the rest of the lines
};
> The same string being the same file is more of an issue. Just
> consider having two different modules/packages, opening the same
> file. You _might_ want them to have different meanings.
Good point. Filehandles opened for string constants should tightly
scoped. (Filehandles opened for scalar variables should have the same
scope as the variable.) I still need to think about this (and get more
advice).
> JE> To my eye angle brackets signify input.
>
> Perhaps but what about Damien's proposal
>
> if ($x < foo() > $y) { ... }
>
> Remember perl has to intuit among, < file >, <, <= , !<, etc.
>
> I'd rather not add to the load.
perlop/"Gory details of parsing quoted constructs" has some detailed
discusion about how this sort of thing is parsed now. The input
operator will fill the <file*glob> niche. Perhaps there should be a
qi<> or i<> quote mechanism as well so that alternate delimiters could
be used.
> However, there is the concept of lazy evaluation that has been
> proposed so you might be able to get your way.
>
> @foo = lazy grep ....
> while( <@foo> ) { ... }
>
> However, I'd rather you limit your proposal to being valid only at a
> single spot in the code. Similar to the .., and ... toggle
> operators. So that different usages of the same string mean different
> filehandles.
What does lazy grep do? How does this apply?
> I'm not quite in favor of the proposal, since DWIMing the meaning of
> a string doesn't seem to be clear. Perhaps you should go through all
> of the possiblities.
>
> You will also have to consider, if the string is to be put through
> magic open? or strictly valid file and directory names. What about
> the proposed URL intuiting? Should that be accepted?
Yep. I hope to put it in v3.
print <'http://dev.perl.org/rfc/51.pod'>;
Jon
--
Knowledge is that which remains when what is
learned is forgotten. - Mr. King
