Re^3: RE on lines read from in-memory scalar is very slow

[Danny]

"(I've noticed on other occasions that making one of my APIs handle-friendly by wrapping optional plain scalars with a file handle and then writing the body of the code to read from handles has introduced a performance hit vs. writing the code to split /\n/ and process the strings directly. It would be really cool if they performed equally)"

Can you make a new thread explaining this? I don't understand.

[NERDVANA]

I'm just saying that I've run into cases where

for (split /\n/, $longstring) {
  ...
}

ran faster than

open my $fh, '<', \$longstring;
while (<$fh>) {
  ....
}

In a perfect world, they would run the same speed (or at least really close). The second one is preferred any time there's a case that you want to run it on a huge file and don't want to load $longstring all into memory at once. The second code solves both cases, but if a majority of your cases are to have it already loaded in memory, then maybe you want to write it the first way for performance.

(If I made a top-level post out of this I'd want to do all the benchmarks and different perl versions, and I'd end up researching the Perl source code and all that, which I don't have time for right now)