Re^3: Regex to match range of characters broken by dashes


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Re^3: Regex to match range of characters broken by dashes

by Cristoforo (Curate)

on Jul 18, 2016 at 01:26 UTC ( [id://1167937]=note: print w/replies, xml )

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in reply to Re^2: Regex to match range of characters broken by dashes
in thread Regex to match range of characters broken by dashes

Thanks for pointing out points in my solution that can be stated cleaner.

This is a bug that was corrected in Perl version 5.18 IIRC. With this correction, lexical variables always work as expected in "(?{ code })" and "(??{ code })" regex constructs.

I wasn't aware of that bug. And your local our $q = $s - 1; fixes that.

it can all be written normally, given that the s/// match regex is, by default, re-compiled on each s/// execution

That is a nice solution! The (??{. . .}) construct wasn't necessary.

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Re^4: Regex to match range of characters broken by dashes
by AnomalousMonk (Archbishop) on Jul 18, 2016 at 04:07 UTC

... local our $q = $s - 1; fixes [the lexical bug].

It can even be fixed a bit more cleanly, and also fold in the added s/// fixup at the end (still runs under 5.8.9):

c:\@Work\Perl\monks\Q.and>perl -wMstrict -le
"my @stops = (2,6);
 ;;
 my $tag = '___';
 ;;
 for (qw(ATCGGATCTGGC  A-C-G--CTGGC)) {
   my $seq = $_;
   printf qq{'$seq' -> };
   $seq =~ s{ ((?: [TAGC] [^TAGC]*){$_} [TAGC]) [^TACG]* }{$1$tag}xms
     for map $_-1, @stops;
   print qq{'$seq'};
   }
"
'ATCGGATCTGGC' -> 'AT___CGGA___TCTGGC'
'A-C-G--CTGGC' -> 'A-C___G--CTG___GC'
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