elisp code for replacing every other occurence in a line?

elisp code for replacing every other occurence in a line?

[Frank Stutzman]

This is probably trivial for emacs-masters, but I'm not one and 
the solution is escaping me...

Say I have a buffer that have intermittant  lines that look like:

a,b,c,DD,e,f,g,DD,h
i,j,k,DD,l,m,n,DD,o

I'm trying to write some lisp code that will change them so that 
they look like:

a,b,c,DD,e,f,g,YY,h
i,j,k,DD,l,m,n,ZZ,o

DD,YY and ZZ will always be the same strings.  These pairs of lines
may not always be found sequentially in the file.  For what its worth,
this buffer is a CSV delimited buffer although I would prefer to do this 
without using any special mdoes.

-- 
Frank Stutzman

Re: elisp code for replacing every other occurence in a line?

[Grant Rettke]

What is the first simple case you want to handle that you would define
as successful?

May you post 3-5 sample tests of how you want it to work and would
know that it is working correctly?
Grant Rettke | AAAS, ACM, ASA, FSF, IEEE, SIAM, Sigma Xi
grettke@acm.org | http://www.wisdomandwonder.com/
“Wisdom begins in wonder.” --Socrates
((λ (x) (x x)) (λ (x) (x x)))
“Life has become immeasurably better since I have been forced to stop
taking it seriously.” --Thompson


On Mon, May 12, 2014 at 12:32 PM, Frank Stutzman <stutzman@cat2.kjsl.com> wrote:
> This is probably trivial for emacs-masters, but I'm not one and
> the solution is escaping me...
>
> Say I have a buffer that have intermittant  lines that look like:
>
> a,b,c,DD,e,f,g,DD,h
> i,j,k,DD,l,m,n,DD,o
>
> I'm trying to write some lisp code that will change them so that
> they look like:
>
> a,b,c,DD,e,f,g,YY,h
> i,j,k,DD,l,m,n,ZZ,o
>
> DD,YY and ZZ will always be the same strings.  These pairs of lines
> may not always be found sequentially in the file.  For what its worth,
> this buffer is a CSV delimited buffer although I would prefer to do this
> without using any special mdoes.
>
> --
> Frank Stutzman
>
>

Re: elisp code for replacing every other occurence in a line?

[Frank Stutzman]

Nevermind....

It took quite a while to get my brain into elisp mode.  Once that happened I 
realized that my solution was write there on the help page for replace-string.
Right there where it says you probably don't want to use replace-string.
Pretty much the only real change I had to do was to use the COUNT option on
search-forward.
-- 
Frank Stutzman

Re: elisp code for replacing every other occurence in a line?

[Robert Thorpe]

Frank Stutzman <stutzman@cat2.kjsl.com> writes:

> Nevermind....
>
> It took quite a while to get my brain into elisp mode.  Once that happened I 
> realized that my solution was write there on the help page for replace-string.
> Right there where it says you probably don't want to use replace-string.
> Pretty much the only real change I had to do was to use the COUNT option on
> search-forward.

You don't necessarily have to write any elisp at all for things like
this.  If you can use replace-string or search-forward then you can use
a macro.  Start recording with F3, do the search and replaces with
something like M-% then finish with F4.  Then do M-x insert-kbd-macro
and it'll give you a bit of elisp code.  You can turn that into a defun
and put into your init file if you want to.

BR,
Robert Thorpe