in reply to HTML Token Diff
in thread HTML Document Comparison

Way cool! Now I can't look too hard at that if I'm going to reimplement it for the column, but way cool!

Regarding the original poster's question, can you get some quantitization of "how much" of the file is changed, like 0 to 100%?

-- Randal L. Schwartz, Perl hacker

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RE: RE: RE: Re: HTML Document Comparison
by mdillon (Priest) on Sep 13, 2000 at 20:49 UTC

    so, now that i've made a few changes, i think you could do this by keeping a running total of the hunk sizes and then comparing it to the number of lines in either the original or the revision. however, i'm not really sure what would be an appropriate heuristic. perhaps showing both $total_deletions / $original_lines and $total_additions / $revision_lines.

    you could also use LCS instead of diff and compare the size of the LCS (Longest Common Subsequence) to the size of the original or revised token list. this would allow you to say roughly "Revision is 80% similar to original" if @LCS / @original == 0.8.

    i have updated my old post to include this heuristic.

RE: RE: RE: Re: HTML Document Comparison
by little (Curate) on Sep 13, 2000 at 20:36 UTC
    merlyn, but how about some luxus in your script as well? ( I mean there always is.) I'm thinking about identifying something like: lines 20 to 26 in document A are not in document B, even if the rest is the same. This sometimes drives me crazy when comparing not Html but other txt.files? But it's just an idea.