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;
}