I would argue against blanket rewriting. A complete rewrite also means a complete QA/Defect resolution cycle. What you are basically looking at is a piece of code that needs a serious refactoring.

The suggestions regarding Unit Testing and using them after each little change is an extremely good one. You will save yourself significant trouble and time by making sure you have several examples of the various outputs based on various inputs; This is true whether you rewrite or not, especially if other processes use the codes output as input.

tilly suggestion regarding breaking code functionality into seperate libraries is very logical. Doing this as part of the refactoring is natural and will increase the potential for the result code to be much easier to maintain.

Martin Fowler has a book devoted to refactoring, Refactoring: Improving the Design of Existing Code. It is a good resource for recipes to look for during refactoring.

Good luck, and a project like this can actually be fun if you approach it with the right perspective.

Edited: footpad, 22 Aug 01, ~21:05 PDT

In reply to Re: Best way to fix a broken but functional program? by Sifmole
in thread Best way to fix a broken but functional program? by idnopheq

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.