vim fold text with spaces in front

Question

I'm trying to customize vim folding style and stuck with indentation. I know it has been asked multiple times here and I use this command (which seem to work for others) to test the appearance of fold:

:set foldtext=' '.foldtext()

This however gives me 'unknown option' error. Apparently, it doesn't accept the string containing only space(s), because this

:set foldtext='mytext'.foldtext()

works fine and adds 'mytext' to the beginning of folds.

Why doesn't it work and what's the way around it?

Answer 1

You just need to escape the space. Use this instead.

:set foldtext='\ '.foldtext()

The space is causing vim to think you want to set foldtext to ' and then '.foldtext() is the next argument to set. However this isn't what you want and the reason the error message is

E518: Unknown option: '.foldtext()

Escaping the space tell vim that foldtext='\ '.foldtext() is one argument instead of two.

Answer 2

You can use the EightHeader plugin if you prefer aligned foldtext. Example from the help:

If you don't like the default 'foldtext' you can customize it by setting to EightHeaderFolds().

For example the closed folds looks like this by default:

```+-- 45 lines: Fold level one
+--- 67 lines: Fold level two

If you would like to change it to this kind:

Fold level one................45 lines
  Fold level two..............67 lines

... then you can use this function:

let &foldtext = "EightHeaderFolds( '\\=s:fullwidth-2', 'left', [ repeat( '  ', v:foldlevel - 1 ), '.', '' ], '\\= s:foldlines . \" lines\"', '' )"