Style Points

japhy — Wed, 01 Nov 2000 02:50:02 +0000

Continue style discussion at the newly created post.

Rob Pengelly — Wed, 01 Nov 2000 01:29:35 +0000

Vorm, I believe that Larry Wall, Perl's creator requested that it be written as Perl, rather than PERL.

Vorm — Wed, 01 Nov 2000 01:21:17 +0000

Well, actually, I'm pretty sure PERL is an acronym, and acronyms are capitalized, so...

Yeah, the split thing was different. Ditto for the no () around the push.

Why use arrays, anyway?

japhy — Wed, 01 Nov 2000 01:19:33 +0000

Anyway, there probably is no need to store all the lines of the file into an array, and then iterate over the array. That takes up memory needlessly. Use a while loop.

open FILE, $filename or die "can't read $filename: $!";
while (<FILE>) {
  # do something with $_
}
close FILE;

japhy — Wed, 01 Nov 2000 01:15:08 +0000

So is your spelling of "Perl", Vorm.

What strikes you as odd about my Perl code? The fact that I didn't send any arguments to split()? The fact that I used the default $_ variable in my for loops?

Err, the fact that I called push incorrectly... that should have been

for (@lines) {
  my @words = split;
  push @list_of_words, \@words;
}

There. Less odd-looking now?

Vorm — Wed, 01 Nov 2000 00:59:54 +0000

Your PERL is weird looking japhy.

Anyways, I'd just do the processes for each array without creating one for each file.

Soft References are BAD!

japhy — Tue, 31 Oct 2000 21:47:47 +0000

That's because $foo$bar = "something" is not valid syntax in Perl. What you're trying to do is:

@{"articles$i"} = (...);

That's called a "soft reference". DO NOT USE THEM. They have one very specific use in Perl, and that is the only time they should be used. Specifically, their use is NOT in this case. You should probably be using an array of references to arrays:

for (@lines) {
  my @words = split;
  # push @list_of_words = \@words; # <-- ERROR
}

Now @list_of_words is an array, each of whose elements are references to an array. To access the data, you'd do something like:

for (@list_of_words) {
  my @data = @$_;  # @{ ... } dereferences an array ref
  # ...
}

For more information on references, read the perlreftut, perlref, perldsc, and perllol documentation (available on your computer or at http://www.perldoc.com/. I also have a small document on using references on my web site at http://www.pobox.com/~japhy/.

UPDATE: check my next post for the correction of that code. Silly japhy...

[Edited by japhy on 10-31-2000 at 08:16 PM]

merlin — Tue, 31 Oct 2000 07:08:52 +0000

well, i have that, but i get a syntax-error...
here's my code:

$i = "1";
foreach $line (@articleslist) {
	open(ARTICLE, "$stuffdirectory/$line") || die "No such file: $line";
		@articles$i = <ARTICLE>;
	close(ARTICLE);
	++$i;
}

'
the error is in line 5 (@articles$i =

Mark Hensler — Tue, 31 Oct 2000 06:48:11 +0000

Vorm-
you forgot one little thing. in your second one (I'm assuming you copied and pasted from the first) you forgot the $i at the end of @articles

$i="1";
foreach $line (@articleslist) {
open(HEH, "<$line");
@articles$i=<HEH>;
close(HEH);

print @articles$i;

++$i;
}

merlin — Tue, 31 Oct 2000 06:39:19 +0000

thanks vorm, you just gave me a nice idea... i think i'll go for two... but still i'll try one too (just for fun)...