Re: RFC 51 (v2) Angle brackets should accept filenames a

>>>>> "JE" == Jon Ericson <[email protected]> writes:

JE> Chaim Frenkel wrote:
>> What does
>> 
>> $foo = <"filename">;    # 1
>> $bar = <"another">;
>> $gaz = <"filename>;     # 2
JE>                            ^ add " here

>> Does #2 get the second line or the first?

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.

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.

>> Can the <> contain a function? 

JE> Of course.  Stick any old list there.

>> Your example seems to indicate that
>> it can. But if it is hard for me to parse visually, I'm not sure
>> how easy it would be for the parser.

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.

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.

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?

<chaim>
-- 
Chaim Frenkel					     Nonlinear Knowledge, Inc.
[email protected]				               +1-718-236-0183