Re^8: regex find and replace with a twist

I don't understand the effort to use split and map in solutions. Even with this latest version of the assumed implied requirement, a good, old s/// seems the best way:

c:\@Work\Perl\monks>perl -wMstrict -le
"my $word = '$-.%aBc&/d-E';
 ;;
 (my $new_word = $word) =~ s{ ([^[:alpha:]]+ | [[:alpha:]]) }{[$1]}xms
+g;
 ;;
 print qq{'$word' -> '$new_word'};
"
'$-.%aBc&/d-E' -> '[$-.%][a][B][c][&/][d][-][E]'
[download]

Give a man a fish: <%-{-{-{-<

Comment on Re^8: regex find and replace with a twist Select or Download Code

Replies are listed 'Best First'.
Re^9: regex find and replace with a twist by talexb (Chancellor) on Jul 18, 2018 at 03:14 UTC
In the end it comes down to readability, and readability depends on the comprehension level of the reader. You have a much higher level of regex-fu than I do, so yours is clear and understandable. I just had to look at it carefully before I could clearly see what it was doing. PS Good job -- that's a very nice piece of code. Alex / talexb / Toronto Thanks PJ. We owe you so much. Groklaw -- RIP -- 2003 to 2013.	[reply]
Re^9: regex find and replace with a twist by dsheroh (Monsignor) on Jul 18, 2018 at 07:19 UTC
I don't understand the effort to use split and map in solutions. As the one who first introduced them, I wasn't making any special effort to use `split` or `map`. As I (mis)understood the spec, it was the most natural approach to a solution. At a human-level description, if you have a string and want to put brackets around each character, do you search the string for characters and, each time you find one, change it to a three-character sequence of the same character preceded and followed by brackets (`$word =~ s/./[$1]/g`); or do you consider the text as a list of characters (`split '', $word`) and put brackets around each of them (`map { "[$_]" }, @chars`)? Personally, if I were doing it by hand, I'd take the latter approach, and I expect pretty much anyone else would, too. But, as already pointed out, I misunderstood the spec as wanting to bracket all characters, not only letters. With that limitation in place, the "treat it as a list of characters, not searching in a string" approach still works with a minor modification, and much more simply than the earlier attempts to fix it: `$new_word = join "", map { $_ =~ /[a-zA-Z]/ ? "[$_]" : $_ } split "", +$word;` [download] Again following the "how would I do it by hand?" approach, this changes the `map` from "put brackets around each character" to "put brackets around characters in a-zA-Z and leave any other characters as-is", thus transforming "`layer123`" to "`[l][a][y][e][r]123`".	[reply] [d/l] [select]