Now this is an interesting problem.

One solution that I could think of right off the bat is to add a marker to the beginning and ending of the replacement string before applying it, and then not allowing the search string to operate in the area bounded by an open/close marker. Remove the markers before emitting the output.

If you do follow this approach, watch out for greedy matching. By your definition, you should never have nested "this is changed" markers, so a minimal match on the search string should suffice.

--MidLifeXis

Please consider supporting my wife as she walks in the 2009 Alzheimer's Walk.

In reply to Re^3: Algorithm to search and replace on data file, based on a table file? by MidLifeXis
in thread Algorithm to search and replace on data file, based on a table file? by koknat

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.