in reply to large hash of regex substitution strings

(Please put your code in <c>...</c> tags. It'll handle escaping the necessary character and it'll place the line breaks for you.)

There's a lot of needless work here. Perl code and regexs are being parsed and compiled over and over again. Also, there's no reason to use /o anymore. It does nothing more than complicate things.

my %chartran = (
   "\xE1" => 'aacute',
   "\xE2" => 'acirc',
   "\xE4" => 'auml',
   "\xC0" => 'Agrave',
   "\xC1" => 'Aacute',
);

my $re = '[' . (join '', keys %chartran) . ']';
$re = qr/$re/;

while (<VRUN>) {
    s/($re)/$chartran{$1}/g;
    print;
}

[download]

Of course, you could simply use core module HTML::Entities's encode_entities method. 

use HTML::Entities qw( encode_entities );

while (<VRUN>) {
    print encode_entities($_);
}

[download]

Replies are listed 'Best First'.
Re^2: large hash of regex substitution strings
by throop (Chaplain) on Oct 06, 2007 at 04:18 UTC
    Hmmmph. I hadn't looked at HTML::Entities before. I'm already used to using CGI (or CGI::Pretty) and its encodeHTML function, which seems to do pretty much the same thing – (Take a string and substitute escaped HTML for the nonstandard characters.) Is there an advantage to using HTML::Entities? Or is it just that it's a smaller standalone module?

    throop

[reply]

      I never looked at CGI's escapeHTML, so I took a peek.

      escapeHTML/unescapeHTML only converts a few characters.
      That means you you can't place unicode characters in an iso-latin-1 document, only iso-latin-1 characters.
      That means any but a few entities won't be understood. For example, it's unable to unescape &eacute;, even if it maps to a character in the specified character set.

      HTML::Entities is familiar with all entities.
      HTML::Entities can numerically encode any range of characters.
      HTML::Entities can decode any range of characters.

      escapeHTML has some workarounds for browser issues and for &quot; being accidentally omitted from HTML 3.2.

[reply]
[d/l]
[select]
Re^2: large hash of regex substitution strings
by scodes (Initiate) on Oct 07, 2007 at 04:47 UTC
    Thanks. What about the following example ? 
    s/^\s+\(Text [aA].* (\d+:\d+ .*$)/\.T1 "$1/g;

    [download]
    I ask as I have about 50 regexs to work with.
    I could build this out like this: 
    
%search (
  1 => "s/^\s+\(Text [aA].* (\d+:\d+ .*$)/",
  2 => .....
);
$replace (
  1 => "/\.T1 \"$1/",
  2 => .....
);

Now I'd like to do something like this, and I know qr// fits
in to the equation, I just dont know how .... yet :)

while <VRUN>   {   
    s/$search/$replace/g;
}

    [download]
    Thanks for taking a further look at this. Thanks again.
[reply]
[d/l]
[select]

      Is there a pattern between the different operations? If not, you might be stuck with

      my @ops = (
   sub { s/^\s+\(Text [aA].* (\d+:\d+ .*$)/\.T1 "$1/g; },
   ...
);

while (<$fh>) {
   foreach my $op (@ops) {
      $op->();
   }
}

      [download]

      The reason it can't be simplified much is the $1 in the replace expression. Often, when reaching this point, it's time to look into a templating system. It's hard to tell if that's the case here since I'm only getting a very small picture of what you are doing.

[reply]
[d/l]
[select]
      Further to the above: 
      %search (
  R1 => "/^\s+\(Text [aA].* (\d+:\d+ .*$)/",
  R2 => .....
);
$replace (
  R1 => "/\.T1 \"$1/",
  R2 => .....
);

while <VRUN>   {   

  foreach $rule ( keys %search )  {

    s/$search{$rule}/$replace{$rule}/g;

  }
}

      [download]
      My only concern is the substring match in R1/S1. Can I use qr// to make this more efficient, and if so, what is the correct syntax. Would qr// be required on both sides of the s// ? Do i need to use an eval or an /ee modifier to get the substitution to happen ? Thanks again all you p'gurus for your help on this :)
[reply]
[d/l]

In Section Seekers of Perl Wisdom