in reply to Re^3: Pattern matching simultaneous substitution
in thread Pattern matching simultaneous substitution

Ok, let me try again with some examples of how data look now (old) and should look (new):
-case 1: only 's' 
old:sssss
new:iiiii

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-case 2: only 's' and 'U' 
old:sssUUss
new:iiiMMoo

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-case 3: only 's' and 'D' 
old:sssDDss
new:oooMMii

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-case 4: 's', 'D' and 'U' (all possible characters) 
old:sssssDDDDDDDssssUUUss
new:oooooMMMMMMMiiiiMMMoo

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OR 
old:sssssUUUUUUUssssDDDss
new:iiiiiMMMMMMMooooMMMii

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For some reason, the code I wrote changes many but not all cases... Not that you cannot see s+D+s+D+s+<code> sequence, or <code>s+U+s+U+s+<code>. <code>D and U alternate.

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Re^5: Pattern matching simultaneous substitution
by choroba (Cardinal) on Jan 05, 2022 at 22:15 UTC
    > Not that you cannot see s+D+s+D+s+ sequence, or s+U+s+U+s+. D and U alternate.

    If you mean "Note" by "Not", than your sample input is invalid, as both the sequences contain sDsDs.

    Also, I think the following works correctly even for the non-alternating sequences in the way you originally showed: 

    my %before = (U => 'I', D => 'O');
my %after; @after{ keys %before } = reverse values %before;
sub subst {
    local ($_) = @_;
    1 while s/(s+)(?=([DU]))/$before{$2} x length $1/e
          | s/(?<=([DU]))(s+)/$after{$1} x length $2/e;

    tr/DU/MM/ or tr/s/I/;
    return $_
}

    [download]
    It uses the bitwise or that doesn't short circuit to try both the substitutions every time while there's anything to replace.

    Tested against:

    Read more... (545 Bytes)

    Might need some tweaking if the specification changes.

    map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]
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[d/l]
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Re^5: Pattern matching simultaneous substitution
by Anonymous Monk on Jan 05, 2022 at 21:09 UTC
    Fixed it after all:
    while(<>)
{
    if($_=~/^>/)
    {
        $id=$_;
        $seq=<>;

        print $id.$seq;
        if($seq=~/^s+$/)
        {
            $seq=~s/s/I/g;
            print $seq;
        }

        else
        {
            while($seq=~/(s+)([U|D]+)(s+)/g)
            {
                $part_before=$1;
                    $len_bef=length($part_before);
                $part_TM=$2;
                $part_after=$3;
                    $len_after=length($part_after);

                if($part_TM=~/U/)
                {
                    $part_bef_new='I' x $len_bef;
                    $part_after_new = 'O' x $len_after;
                }
                elsif($part_TM=~/D/)
                {
                    $part_bef_new='O' x $len_bef;
                    $part_after_new = 'I' x $len_after;
                }
                $seq=~s/$part_before/$part_bef_new/;
                $seq=~s/$part_after/$part_after_new/;
            }

            $seq=~s/U/M/g;
            $seq=~s/D/M/g;
            print $seq;
        }
    }
}

    [download]

    Thank you for your time!
[reply]
[d/l]
      I don't think your code works. When I run it for input 
      ssDDssUUss

      [download]

      it returns 

      OOMMIIMMss

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      while you previously claimed the correct output is 

      OOMMIIMMOO

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      Similarly, 

      ssUUssDDss

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      is transformed into

      IIMMOOMMss

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      while the correct output should be

      IIMMOOMMII

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      map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]
[reply]
[d/l]
[select]
        You were right, thanks! I added a last regex substitution to cover the last part :)
        Thanks again!
[reply]

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