#!/usr/bin/perl
use strict;
use warnings;

my @text = split /\n/, << 'TEXT';
Regular expressions have the undeserved reputation
of being abstract and difficult to understand.
TEXT

my @regexlist = split /\n/, << 'REGEX';
s/a/A/g
s/i/I/g
s/e/E/g
REGEX

my $regex = join '|', @regexlist;

while (<@text>) {
//    apply $regexes somehow, the fastest way possible;
}