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I'm looking for a way to precisely set the cursor position given a virtual column.

Is there only :exe "normal! ".vcol."|"?

NB: I need virtual columns as they're the only thing that I'm able to compute correctly in a context where there are multi-byte characters that occupy only one column, and tab characters that spawns over several columns.

Regarding the context, I should be more explicit. If I'm looking for a function, it's partly out of curiosity, partly to avoid translating a tuple of coordinates (that I already have thanks to getpos(a_mark)) into something else, partly for style consistency: I'm trying to fix/enhance a plugin where I try to use functions. This implies I cannot expect something as the virtual editing mode to be in a state or in another: plugins need to work whatever the end-user choose for her/his vim options. Yet, it's true I could change it momentarily and restore it in a finally statement.

Also, I'm not in the general case where I may end up in the middle of a tabulation. Any position, I want to jump to, is accessible without 'virtualedit' being set. The (computed) position matches a placeholder in an expanded and re-indented code snippet.

  • I don't often use virtual columns so it might be a dumb comment but can't you do what you want with :h setpos() and use the off entry of the list taken as parameter? – statox Oct 12 '18 at 14:21
  • According to the documentation, "off" relates to virtualedit mode, which is not my situation. – Luc Hermitte Oct 12 '18 at 14:27
  • Ok I thought virtualedit was mandatory to use virtual columns, my bad :) – statox Oct 12 '18 at 14:30
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    No. It's unrelated. In \t/*«»*/ if () {, getcursorpos() returns [0, 2, 14, 0, 19] when the cursor is on the (. The byte index is 14, but the actual (virtual...) column is 19 -- with &ts==8 – Luc Hermitte Oct 12 '18 at 14:33
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    I should have stated my context more explicitly. I'm trying to fix a plugin that may be used by anybody with any possible setting. This means I cannot expect options to be a in certain state. The easiest solution for me would have been "tabs users cannot use my plugin"... Here however, I must admit I could set virtualedit momentarily. I've to think about that. – Luc Hermitte Oct 13 '18 at 7:58
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Using the Tab example, let's say my line number 10 starts with a tab character (denoted by > and - for each of the three virtual columns that follow):

10: >---foo

This will place the cursor in (virtual) column 3:

set virtualedit=all
call cursor([10, 1, 2])

The list is [lnum, col, off]. lnum is line number. col is non virtual column and off is offset beyond col (this is the secret sauce to get to a virtual column).

Result:

10: >---foo
      ^
      |_____ cursor here

Note that without the virtualedit setting the cursor would be placed in column 1.


My first submission used setpos() instead until I realized that cursor() is more straightforward...

call setpos(".", [0, 10, 1, 2])

"." means "set cursor position" (as opposed to a mark). The list is [bufnum, lnum, col, off]. A bufnum value of 0 indicates current buffer. The rest is identical to the parameters for cursor().

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    While it's not exactly what I'm looking for, it gives me a strong hint why virtual columns are ignored by these functions when we are not in virtual editing mode. Thanks. – Luc Hermitte Oct 23 '18 at 12:41
  • I think that what @LucHermitte is trying to do is: given the input 5, place the cursor on the f He’s not trying to find a way to place the cursor on “column” 3. (That’s what he means by “The places that I want to jump to exist”) – Rich Oct 23 '18 at 19:53
  • @Rich, it's indeed the case. B Layer wrote his (her?) answer before I provide more details on my exact use case. – Luc Hermitte Oct 23 '18 at 20:04
  • @LucHermitte Ah, I didn’t notice the times (and dates!) on things. – Rich Oct 23 '18 at 20:17
  • Thanks @LucHermitte, I'm glad it was helpful if somewhat off the mark. I appreciate the accept/vote. – B Layer Oct 24 '18 at 2:40

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