Dear Monks,

My question is about a faster way to do phrase matching in a sentence. The usual standard way would be:

$sentence="Jack and Jill went up the hill to fetch a pail of water.";
$sentence=~/pail of water/\#pail of water\#/g; #tag the phrase 'pail of water' in the sentence.

However, the above method becomes too slow when I have a long list of phrases and also sentences. If I have single words instead of phrases, I could use hash matching on 'split' sentence words, such as:

@temp=split(' ', $sentence);
my %hash=("pail of water"=>1);

foreach my $i (@temp) {
	if ($hash{$i}) {
		---
	}
}

However, this method cannot be applied to phrases. Can something similar/faster be used for phrase tagging of sentences?

On a related note, how to club the words of the marked phrase in the sentence as a single unit (i.e. the phrase appears in a single array element when the split is done on the sentence on the space character).

Thanks.