Re: Emacs: adding 1 to every number made of 2 digits inside a marked region.

[Michael Heerdegen]

Hongyi Zhao <hongyi.zhao@gmail.com> writes:

> Imagine I've got the following in a text file opened under Emacs:
>
> some    34
> word    30
> another 38
> thing   59
> to      39
> say     10
> here    47
>
> and I want to turn into this, adding 1 to every number made of 2 digits:
>
> some    35
> word    31
> another 39
> thing   60
> to      40
> say     11
> here    48

You might want to give Calc a try for such things.  It doesn't perfectly
handle the editing part though since it doesn't know about rectangle
commands (AFAICT - at least for insertion).

So here is how I would do it:

- mark the rectangular region spanning the numbers
- `C-x * r': this will grab the number column as a matrix and pop up
  Calc
- `1 RET +': will add 1 to all entries

You now have the result as a matrix.  What you have to do now manually
using conventional rectangle commands is to kill the original numbers
from the buffer (they are already marked, so `C-x r k'), and then kill
and yank the numbers as rectangle from the Calc buffer.

Calc also allows to add numbers in a row or column in any buffer in a
similarly easy way.  The Calc tutorial has some examples doing such
things.

Michael.