Just as a text file is both a set of lines and a stream of bytes, an HTML document is both a tree and a stream of elements. HTML::Parser extracts the latter, which is equivalent to walking the DOM tree in some order. The advantage of using HTML::Parser for an application like this is the same as the advantage of processing a text file line-by-line without reading the whole file into memory.

While it is unlikely that an HTML document would not fit into memory on a client, our questioner could be building something that runs on a server, with an instance of the program for each concurrent client connection which can quickly become very large in aggregate if many clients are active. In this case, building the entire tree in memory is unnecessary because the transformation to be applied is very simple: find and mark ocurrances of certain text in a finite sliding window. If this is running on a server, building the DOM tree in memory is both wasteful and foolish, creating an opportunity for easy DoS attacks.

Put simply, if you do not actually need the DOM tree, do not waste time and memory building it!

In reply to Re^3: Match text from txt to html by jcb
in thread Match text from txt to html by corfuitl

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.