Perl Style: Closures

Jan 1, 1998 by Tom Christiansen

• Clone similar functions using closures.

      # from MxScreen in TSA
      no strict 'refs';
      for my $color (qw[red yellow orange green blue purple violet]) {
          *$color = sub { qq<<FONT COLOR="\U$color\E">@_</FONT>> };
      }
      undef &yellow;      # lint happiness
      *yellow = \&purple; # function aliasing
  

• Or similarly:

      # from psgrep (in TSA, or PCB 1.18)
      my %fields;
      my @fieldnames = qw(FLAGS UID PID PPID PRI NICE SIZE
                          RSS WCHAN STAT TTY TIME COMMAND);
  
      for my $name (@fieldnames) {
          no strict 'refs';
          *$name = *{lc $name} = sub () { $fields{$name} };
      }
  

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Copyright © 1998, Tom Christiansen All rights reserved.