in reply to Re: How best to tell when my hash is "full" (all values defined)?
in thread How best to tell when my hash is "full" (all values defined)?

bart, thanks for the reply. grep is another one of those functions that I don't know well. Continuing on our theoretical tangent, if you will, could one golf your approach down to 
grep !defined, values %stats || last;

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as a quick and simple escape clause?

For some reason I like the idea of predeclaring what data I want (by mnemonic), and "filling" an empty data structure, as opposed to creating the key-value pairs on the fly. It's just mental I guess, though I suppose it may increase readability somewhat. Also, is there a memory or performance penalty if you don't predeclare the numer of elements in a hash? Returning the scalar of the hash gives me 4/8 with the predeclared version; I suppose I will try it the other way and report back.

Thanks again to everyone,
T.

I like computer programming because it's like Legos for the mind.
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Re^3: How best to tell when my hash is "full" (all values defined)?
by OfficeLinebacker (Chaplain) on Dec 18, 2006 at 15:26 UTC
    Hi, 
      grep !defined, values %stats || last;
  my $swvn=grep !defined, values %stats;
  print $swvn;
  $swvn || last;

    [download]
    produces 
    3
2
2
0
    so that means it doesn't work. The "fix" is to scalar() what grep() returns: 
      scalar(grep !defined, values %stats) || last;
  my $swvn=grep !defined, values %stats;
  print $swvn;
  $swvn || last;

    [download]
    produces 
    3
2
2
    I'll check the memory consuption thing shortly.
    I like computer programming because it's like Legos for the mind.
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Re^3: How best to tell when my hash is "full" (all values defined)?
by OfficeLinebacker (Chaplain) on Dec 18, 2006 at 15:41 UTC
    Hi again :) The following code (I plan to implement the piped open shortly, but just used what I have to test the memory usage of the hashes in the two approaches) 
    my @raw=`top -b -n 1`;
my (%stats,%stats2);
my $expected_keys = 5;
@stats{'users','load','tmem','fmem','runproc'} = ();
my $its=0;

foreach my $line (@raw){
  if ($line =~ /up\s.+\s(\d+)\suser.+\s+load\saverage:\s+(\d+\.\d{2}),
+/){
    $stats{users}=$1;
    $stats{load}=$2;
    $stats2{users}=$1;
    $stats2{load}=$2;
  }
  elsif ($line =~ /(?:Tasks|processes):.+\s+(\d+) running/i){
    $stats{runproc}=$1;
    $stats2{runproc}=$1;
  }
  elsif ($line =~ /^Mem:\s+(\d+)k\s+(?:total|av),.+used,\s+(\d+)k\s+fr
+ee/){
    $stats{tmem}=$1;
    $stats{fmem}=$2;
    $stats2{tmem}=$1;
    $stats2{fmem}=$2;
  }
  $its++;
  print scalar(%stats2);
  print scalar(%stats);
  (scalar(keys(%stats2)) == $expected_keys) && last;
} ## end foreach my $line (@raw)

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    outputs 
    
2/8
4/8
2/8
4/8
2/8
4/8
4/8
4/8
    So the memory usage is no different (correct me if I am wrong--my understanding is that the number we are worried about (if we're worried about memory consumption) is the divisor).

    I'll go ahead and make the call to `top` a piped open and have done with it. Thanks for your help (everyone who posted).

    T.
    I like computer programming because it's like Legos for the mind.
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