Beefy Boxes and Bandwidth Generously Provided by pair Networks
Syntactic Confectionery Delight
 
PerlMonks  

Re^4: How to replace Tab with spaces not altering postion

by Aristotle (Chancellor)
on Oct 14, 2002 at 15:33 UTC ( #205118=note: print w/ replies, xml ) Need Help??


in reply to Re: Re^2: How to replace Tab with spaces not altering postion
in thread How to replace Tab with spaces not altering postion

$_ = "You\tare\tmaking\ttoo\tmany\tassumptions...";

Makeshifts last the longest.


Comment on Re^4: How to replace Tab with spaces not altering postion
Download Code
Re: Re^4: How to replace Tab with spaces not altering postion
by petral (Curate) on Oct 15, 2002 at 15:01 UTC
    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

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://205118]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others drinking their drinks and smoking their pipes about the Monastery: (12)
As of 2014-10-23 18:52 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    For retirement, I am banking on:










    Results (128 votes), past polls