nvim_win_get_config returns table value for row and col instead of number

[mtbrock]

Problem

vim.api.nvim_win_get_config returns table values for row and col:

{
  anchor = "NW",
  col = {
    [false] = 10,
    [true] = 3
  },
  external = false,
  focusable = true,
  height = 20,
  relative = "editor",
  row = {
    [false] = 10,
    [true] = 3
  },
  width = 20,
  zindex = 50
}

You have to access row[false] and col[false] to get the real value.

Steps to reproduce

Write to file:

-- config_test.lua
local bid = vim.api.nvim_create_buf(true, false)
local wid = vim.api.nvim_open_win(bid, true, {
    relative = 'editor',
    width = 20,
    height = 20,
    row = 10,
    col = 10,
})

local config = vim.api.nvim_win_get_config(wid)
print(vim.inspect(config))

Run the file:

nvim -u NORC -c 'luafile %' config_test.lua

Expected behavior

I expect row and col to be numbers, not tables.

Neovim version (nvim -v)

0.9.1

Vim (not Nvim) behaves the same?

n/a

Operating system/version

Arch Linux (kernel version 6.4.4-arch1-1)

Terminal name/version

kitty 0.28.1

$TERM environment variable

tmux-256color

Installation

Arch Extra repo

[seandewar]

The row and col values are fractional, but Lua numbers with integer values are normally converted to Vim script numbers (integers). The [true]=3 field ([vim.type_idx]=vim.types.float) is there to preserve the fact that it should be converted to a float if sent to Vim script.

As a Vim script number would still be accepted as a float value in the API, preserving this information doesn't seem too useful here?

[zeertzjq]

I don't think this behavior should be changed. The same behavior also applies to other functions like nvim_eval and nvim_get_var, where it is actually needed to distinguish a Float from a Number, and there is no reason to have a special case for nvim_win_get_config.

See also :h lua-special-tbl

                                                              *lua-special-tbl*
4. Table with `vim.type_idx` key may be a dictionary, a list or floating-point
   value:
   - `{[vim.type_idx]=vim.types.float, [vim.val_idx]=1}` is converted to
     a floating-point 1.0. Note that by default integral Lua numbers are
     converted to |Number|s, non-integral are converted to |Float|s. This
     variant allows integral |Float|s.
   - `{[vim.type_idx]=vim.types.dictionary}` is converted to an empty
     dictionary, `{[vim.type_idx]=vim.types.dictionary, [42]=1, a=2}` is
     converted to a dictionary `{'a': 42}`: non-string keys are ignored.
     Without `vim.type_idx` key tables with keys not fitting in 1., 2. or 3.
     are errors.
   - `{[vim.type_idx]=vim.types.array}` is converted to an empty list. As well
     as `{[vim.type_idx]=vim.types.array, [42]=1}`: integral keys that do not
     form a 1-step sequence from 1 to N are ignored, as well as all
     non-integral keys.

[mikesmithgh]

Thank you for the comments. It took me a couple times of reading this and the docs to understand what is going on so I'll put my understanding here in case it helps anyone else who comes across this in the future.

Given the result:

  col = {
    [false] = 10,
    [true] = 3
  },

Reading help example :h lua-special-tbl

{[vim.type_idx]=vim.types.float, [vim.val_idx]=1}` is converted to
     a floating-point 1.0. 

This looks confusing at first, but those are just variables.

• :=vim.type_idx = true
• :=vim.types.float = 3
• :=vim.val_idx = false

So, given a lua table with two elements that have the keys true and false, this is recognized as the special table with a value and type.

Back to the example,

  col = {              col = {                    col = {               
    [false] = 10,  ->    [vim.val_idx] = 10,  ->    [vim.val_idx] = 10,  
    [true] = 3     ->    [vim.type_idx] = 3   ->    [vim.type_idx] = vim.types.float   
  },                   },                         },                    

col is a special table, with a value of 10 and a type of float.

[roycrippen4]

For anyone else ending up here like I did. If you need the row, col values from vim.api.nvim_win_get_config(winnr) you would do the following:

local config = vim.api.nvim_win_get_config(winnr)
local row = config.row[vim.val_idx]
local col = config.col[vim.val_idx]

[zeertzjq]

Fixed by #27284