Beefy Boxes and Bandwidth Generously Provided by pair Networks
Your skill will accomplish
what the force of many cannot
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
Right, I was hurrying to put it up and leave.   Forgot to point out it only works for normal input files where each line ends in a newline.

Actually, your algorithm solves the problem without abandoning regexen.   Unless we're missing something, Larry was thinking along the lines of bart's logic above, that you have to know the new length of the line up to this point.   But you are just depending on the text in front of the present tab(s) to be aligned either with the beginning of the line or the previous tab stop, so there is no need to consider the entire preceding line segment:
$ perl -we'$_="\t\tYou\tare\tmaking\t\ttoo\tmany\tassumptions...\t\t"; s/(^|[^\t]+)(\t+)/$1." " x (length($2) * 8 - (length($1) & 7))/ge; print' You are making too many assump +tions... $ ( s/(.*?)(\t+)/...
is simpler but presumably less efficient (which was your initial concern).   However, note that it will work correctly on a multiline string:
$ perl -we'$_="\t\tYou\tare\tmaking\t\ttoo\n\tmany\tassumptions...\t"; s/(.*?)(\t+)/$1." "x(length($2)*8-(length($1)&7))/ge; print' You are making too many assumptions... $


  p

In reply to Re: Re^4: How to replace Tab with spaces not altering postion by petral
in thread How to replace Tab with spaces not altering postion by juo

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!
  • 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, 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, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • Outside of code tags, you may need to use entities for some characters:
            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.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others scrutinizing the Monastery: (13)
    As of 2014-10-23 18:36 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      For retirement, I am banking on:










      Results (127 votes), past polls