Schwartzian Transform

• Sort list of items by some non-apparent feature

• Example: Sort filenames by last-modified date

• The obvious method:

        sort { -M $b <=> -M $a } 
             (readdir D);

• It calls -M over and over on the same files

• Idea: Maybe we can speed this up as follows:

  1. Construct data structure with both names and dates

  2. Sort by date

  3. Throw away dates

Next

Copyright © 2003 M. J. Dominus