feature: select nth item in the completion list, and number items

[theol0403]

Feature Description

Thank you for this incredible plugin! I am honestly blown away by the modularity, structure, and expressive configuration you've built into this.

I am requesting the feature of showing item numbers inside the completion window - should not be too hard with your components system, and additionally a command to "select nth item".

Example (with cmp):

Benefits of displaying item numbers:

• ability to quickly count number of times to hit Down/C-n/Tab
• ability to provide context for a "select nth item" command/keybind
• support people with screen readers

This has been implemented in this PR to nvim-cmp: hrsh7th/nvim-cmp#1491

Related:

• Can one make cmp display numbers in the menu? hrsh7th/nvim-cmp#1112
• Select nth item in the completion list, and number items hrsh7th/nvim-cmp#1491 (comment)
• Being able to quickly choose the completion item with Alt+Number hrsh7th/nvim-cmp#1482

[max397574]

what I think this would require

1. allow confirming items based on visible position
2. pass position in the window to the ctx used for components

[Saghen]

Here's how I configured it locally, I'll add it to the readme

keymap = {
  preset = 'default',
  ['<A-1>'] = { function(cmp) cmp.accept({ index = 1 }) end },
  ['<A-2>'] = { function(cmp) cmp.accept({ index = 2 }) end },
  ['<A-3>'] = { function(cmp) cmp.accept({ index = 3 }) end },
  ['<A-4>'] = { function(cmp) cmp.accept({ index = 4 }) end },
  ['<A-5>'] = { function(cmp) cmp.accept({ index = 5 }) end },
  ['<A-6>'] = { function(cmp) cmp.accept({ index = 6 }) end },
  ['<A-7>'] = { function(cmp) cmp.accept({ index = 7 }) end },
  ['<A-8>'] = { function(cmp) cmp.accept({ index = 8 }) end },
  ['<A-9>'] = { function(cmp) cmp.accept({ index = 9 }) end },
},
completion = {
  menu = {
    draw = {
      columns = { { 'item_idx' }, { 'kind_icon' }, { 'label', 'label_description', gap = 1 } },
      components = {
        item_idx = {
          text = function(ctx) return tostring(ctx.idx) end,
          highlight = 'BlinkCmpItemIdx' -- optional, only if you want to change its color
        }
      }
    }
  }
}

Thank you for this incredible plugin! I am honestly blown away by the modularity, structure, and expressive configuration you've built into this.

❤️