Re: Using a regex as a hash key

Either keep your original key $regex around,

my $regex=qr/^Device(\s)+Configuration/;
...
my $result = $functions{$regex}->($var2);
[download]

or traverse the hash as usual:

my $result = undef;
for (keys %functions) {
  if (this_is_the_key_I_want($_)) {
    $result = $functions{$_}->($var2);
    last;
  }
}
[download]

The check for this_is_the_key_I_want() is optional of course, or you could scan the regex itself as if it were a string, such as /Config/.

--
[ e d @ h a l l e y . c c ]

Comment on Re: Using a regex as a hash key Select or Download Code

Replies are listed 'Best First'.
Re^2: Using a regex as a hash key by ikegami (Patriarch) on Jun 06, 2007 at 16:57 UTC
`%functions` is a Tie::RegexpHash, not a normal hash.	[reply] [d/l]
Re^3: Using a regex as a hash key by halley (Prior) on Jun 06, 2007 at 17:04 UTC
ikegami, I recognized that it's a TRH, but it still behaves like a hash including iteration, as well as the extra features and odd non-1:1 key behavior. If he doesn't have anything for a key (his missing `$val1`), he'll have to start somewhere. Perhaps I should have said he could just assign `$val1 = 'Devices Configuration for Hard Drives'` to pick out one particular key, or the hail-mary dispatch loop that citromatik offers where you just throw any old `$_` in there and hope it sticks. -- `[ e d @ h a l l e y . c c ]`	[reply] [d/l] [select]
Re^4: Using a regex as a hash key by ikegami (Patriarch) on Jun 06, 2007 at 17:12 UTC
Sorry, it sounds like I needed to be more explicit. `%functions` is a Tie::RegexpHash, so your suggestion of `$functions{$regex}->($var2);` is wrong — Use a normal has for that — and a step in the wrong direction. The key for lookups should not be a regexp, but a value to match against the existing keys. Looping over all the keys is even worse. The whole point of Tie::RegexpHash is to save you from doing that.	[reply] [d/l] [select]