In French (and other european languages) we often need to make accent-insensitive comparisons. For example, users of a web site will type andromede in a search box and expect that to match andromède.

This code creates accent-insensitive lc and uc functions. They work like the builtins but get rid of any accents.

Usage: 

    print iso_8859_1_lc("andromède");   # prints "andromede";
    print iso_8859_1_uc("andromède");   # prints "ANDROMEDE";

[download]
use strict;
my %iso_8859_1_accents = (
    a => [ qw(à á â ã ä å À Á Â Ã Ä Å) ],
    c => [ qw(ç Ç) ],
    e => [ qw(è é ê ë È É Ê Ë) ],
    i => [ qw(ì í î ï Ì Í Î Ï) ],
    n => [ qw(ñ Ñ) ],
    o => [ qw(ò ó ô õ ö ø Ò Ó Ô Õ Ö Ø) ],
    u => [ qw(ù ú û ü Ù Ú Û Ü) ],
    y => [ qw(ý Ý) ],
);
# build translation strings
my (%in, %out);
for my $letter ('a'..'z') {
    my $uletter = CORE::uc $letter;
    # translate non-accented letters
    $in{uc}  .= $letter;
    $out{lc} .= $letter;
    $in{lc}  .= $uletter;
    $out{uc} .= $uletter;
    if (my $ra_accented = $iso_8859_1_accents{$letter}) {
        my $in = join '', @$ra_accented;
        $in{lc} .= $in;
        $in{uc} .= $in;
        $out{lc} .= $letter  x @$ra_accented;
        $out{uc} .= $uletter x @$ra_accented;
    }
}
# build translation subroutines
for my $type (qw(lc uc)) {
    my $sub = qq!
        sub iso_8859_1_$type {
           (my \$s = shift) =~ tr/$in{$type}/$out{$type}/;
           \$s
        }
    !;
    eval $sub;
}

[download]

In reply to Accent-insensitive case conversion by echo

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.