How to soft wrap at column number greater than window width?

Question

Imagine a 30-character line shown in a 20-character wide window. How can I soft wrap it at the 25th column?

With :set nowrap

|01234567890123456789|0123456789
|       window       |

After scrolling till 25th character.

01234|56789012345678901234|56789
     |       window       |

Desired behaviour:

01234|56789012345678901234|
     |56789               |
     |       window       |

I tried :set columns with a large number but it messed up other elements like statusline.

A similar question instead concerns with setting column number smaller than the window width.

Answer 1

I thought I found a good example of what can't be done with Vim. (Un)fortunately I was wrong.

The specified behavior can be accomplished by:

1. Concealing first n characters of every line. E.g. :syn match Concealed '^.\{25\}' conceal
   1. n is determined by the current 1 + virtcol(".") - wincol().
   2. This needs to be updated on every WinScrolled (Neovim only) event.
2. Setting concealcursor=nvic.
3. :set wrap