Re^2: How can I make a string unique (quicker than my approach at least)

I use that snippet sometimes since some older version of List::Util do not include a uniq function.

The code means:

sub uniq {
   my %h;    # Keep track of things seen.
   
   grep {         # 4: Return items seen only once.

     not $h{$_}++ # 2: Item is not (yet) be seen.
                  # 3: ++ would then say item was seen.
   } @_;          # 1: For each input...
}
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Comment on Re^2: How can I make a string unique (quicker than my approach at least) Download Code

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Re^3: How can I make a string unique (quicker than my approach at least) by Timka (Acolyte) on Apr 03, 2024 at 04:38 UTC
Input: `cat in ID1 nick-john-helena ID2 george-andreas-lisa-anna-matthew-andreas-lisa ID3 olivia-niels-peter-lars-niels-lars-olivia-olivia` [download] Code: `perl -MList::Util=uniq -ple ' s/ ^ # Beginning of line (BOL). \w+ # Any "words". \s+ # Any whitespace (like tabs). \K # "Keep" whats to the left. (\S+) # Capture and replace next non whitespace (words). / join "-", # 4: n1-n2-n3 uniq # 3: [ "n1", "n2", "n3" ] split "-", # 2: [ "n1", "n2", "n1", "n3" ] $1 # 1: n1-n2-n1-n3 /xe # Freespace regex and eval replacement. ' in` [download] Output: `ID1 nick-john-helena ID2 george-andreas-lisa-anna-matthew ID3 olivia-niels-peter-lars` [download]	[reply] [d/l] [select]

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Re^3: How can I make a string unique (quicker than my approach at least)
by Timka (Acolyte) on Apr 03, 2024 at 04:38 UTC

Input:

cat in

ID1 nick-john-helena
ID2 george-andreas-lisa-anna-matthew-andreas-lisa
ID3 olivia-niels-peter-lars-niels-lars-olivia-olivia
[download]

Code:

perl -MList::Util=uniq -ple '
  s/
     ^      # Beginning of line (BOL).
     \w+    # Any "words".
     \s+    # Any whitespace (like tabs).
     \K     # "Keep" whats to the left.
     (\S+)  # Capture and replace next non whitespace (words).
   /
     join "-",   # 4: n1-n2-n3
     uniq        # 3: [ "n1", "n2", "n3" ]
     split "-",  # 2: [ "n1", "n2", "n1", "n3" ]
     $1          # 1: n1-n2-n1-n3
   /xe           # Freespace regex and eval replacement.
' in
[download]

Output:

ID1 nick-john-helena
ID2 george-andreas-lisa-anna-matthew
ID3 olivia-niels-peter-lars
[download]

[reply]
[d/l]
[select]