Question

Let’s assume you have a cursor at a closed fold as in the picture.

alt text http://dl.getdropbox.com/u/175564/foldEdit.png

How can you edit the title of SMALLAPPS without opening the fold in Vim?

Answer 1

Do you want to edit the first line of the folded block, or the string that appears when the fold is closed? If it’s the former, I don’t think you can do it without opening the fold. If it’s the latter, then have a look at the foldtext option. It can be any expression. This expression is evaluated to create this string.

From the docs:

‘foldtext’ is a string option that
specifies an expression. This
expression is evaluated to obtain the
text displayed for a closed fold.
Example:

:set foldtext=v:folddashes.substitute(getline(v:foldstart),'/\\*\\\|\\*/\\\|{{{\\d\\=','','g')

This shows the first line of the fold,
with “/“, “/” and “{{{” removed.
Note the use of backslashes to avoid
some characters to be interpreted by
the “:set” command. It’s simpler to
define a function and call that:

:set foldtext=MyFoldText()
:function MyFoldText()
:  let line = getline(v:foldstart)
:  let sub = substitute(line, '/\*\|\*/\|{{{\d\=', '', 'g')
:  return v:folddashes . sub
:endfunction

An alternative is using the marker folding method. With it, you can enter any string before the fold marker and it will appear when the fold is closed.

From the docs:

Markers in the text tell where folds
start and end. This allows you to
precisely specify the folds. This
will allow deleting and putting a
fold, without the risk of including
the wrong lines. The ‘foldtext’
option is normally set such that the
text before the marker shows up in the
folded line. This makes it possible to
give a name to the fold.

Markers can have a level included, or
can use matching pairs. Including a
level is easier, you don’t have to add
end markers and avoid problems with
non-matching marker pairs. Example:

/* global variables {{{1 */
int varA, varB;