RegEx to remove carriage returns between tags

Question

I\'ve stumped myself trying to figure out how to remove carriage returns that occur between

tags. (Technically I need to replace them with spaces, not

Answer 1

This is the "almost good enough" lexing solution promised in my other answer, to sketch how it can be done. It makes a half-hearted attempt at coping with attributes, but not seriously. It also doesn't attempt to cope with unencoded "<" in attributes. These are relatively minor failings, and it does handle nested P tags, but as described in the comments it's totally unable to handle the case where someone doesn't close a P, because we can't do that without a thorough understanding of HTML. Considering how prevalent that practice still is, it's safe to declare this code "nearly useless". :)

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

while ($html !~ /\G\Z/cg) {
  if ($html =~ /\G(]*>)/cg) {
    $output .= $1;
    $in_p ++;
  } elsif ($html =~ m[\G(
)]cg) {
    $output .= $1;
    $in_p --; # Woe unto anyone who doesn't provide a closing tag.
    # Tag soup parsers are good for this because they can generate an
    # "artificial" end to the P when they find an element that can't contain
    # a P, or the end of the enclosing element. We're not smart enough for that.
  } elsif ($html =~ /\G([^<]+)/cg) {
    my $text = $1;
    $text =~ s/\s*\n\s*/ /g if $in_p;
    $output .= $text;
  } elsif ($html =~ /\G(<)/cg) {
    $output .= $1;
  } else {
    die "Can't happen, but not having an else is scary!";
  }
}