Re: renumbering numeric comments

[Yuri Khan]

On Tue, Oct 28, 2014 at 7:59 AM, Steven Arntson
<steven@stevenarntson.com> wrote:

> In Lilypond, measure numbers are usually (so far in my experience)
> entered as comments at the end of a line in the form `%m__':
>
> These "%m_" numbers are very useful in debugging when the "code" is
> compiled. However, in the above case I later inserted two new measures:
>
>          \tempo 4=100
>          e4 d e8 f | %m1
>          \tempo 4=130
> ----->   g8 f e d e f |
> ----->   e d c b c d |
>          <c a>2. | %m2
>          <d e,>2 ~ <d e,>8 e | %m3
>          ...
>
> Renumbering everything by hand is a lot of work, because the piece is
> many measures long.

1. Select the part of document you want to renumber in, or go the the
beginning of the buffer to renumber throughout the whole document.
2. Hit C-M-% (for “query-replace-regexp”).
3. Compose a regular expression that matches the parts of text you
want to replace, with some context. I don’t know Lilypond and assume
that measures end with a vertical bar and by convention it’s the last
significant character on the line, followed by a single space,
followed by a percent sign, then the letter m, then a sequence of
digits until the end of line. A new measure will end at the vertical
bar, with the space and comment omitted. So the regexp is: “|\(
%m[0-9]+\)?$”. Enter this as the replace regexp.
4. In the replacement string, use the \# marker where you want a
sequential number inserted: “| %m\#”

This is almost what you want but numbers starting with 0. If you want
1-based numbering, you’ll need to surround the \# marker with an
expression that adds 1: “| %m\,(+ 1 \#)”

The part after “\,” can be any Emacs Lisp expression. The one above
just happens to add (+) one (1) to the number of replacements done
(\#) and can be abbreviated as “(1+ \#)”. (If you wanted to renumber
starting with 200, you would write “(+ 200 \#)”, and for numbering
starting with 301 and using only odd numbers, “(+ 301 (* 2 \#))”.)

Final recipe:

query-replace-regexp
|\( %m[0-9]+\)?$
| %m\,(1+ \#)