feat(ui): use vim.ui.select for :tselect, z= #39478

Problem:
`:tselect` and `z=` (spell suggest) have their own bespoke select menus.

Solution:
- Delegate to `vim.ui.select` instead.
- Bonus:
  - `:tselect` gains mouse support. `print_tag_list` didn't suport mouseclick.

This causes some minor regressions, which are not blockers:

- `z=` no longer draws the list right-left if 'rightleft' is set.
  - TODO: can/should `vim.ui.select` / `vim.fn.inputlist()` handle that?
- `:tselect`
  - No "column" headings (`# pri kind tag file`).
  - No highlighting: (HLF_T: tag name, HLF_D: file, HLF_CM: extra fields).
  - TODO: can `vim.ui.select()` support highlighted chunks (`[[text, hl_id], ...]`) ?

fix https://github.com/neovim/neovim/issues/25814
fix https://github.com/neovim/neovim/issues/31987

runtime/lua/vim/_core/spell.lua

@@ -0,0 +1,36 @@
+local select_blocking = require('vim._core.ui').select_blocking
+local N_ = vim.fn.gettext
+
+local M = {}
+
+--- @class vim._core.spell.Suggestion
+--- @field word string The suggested replacement.
+--- @field extra? string Text replaced when wider than the bad span.
+--- @field score integer Primary score.
+--- @field altscore? integer Secondary score (only set when 'spellsuggest' contains "double" or "best").
+--- @field salscore? boolean True if the score came from sound-alike comparison (only set alongside `altscore`).
+
+--- Called from `spell_suggest()` (`z=`) to let the user pick from `items` via
+--- |vim.ui.select()|.
+---
+--- @param items vim._core.spell.Suggestion[]
+--- @param bad string The misspelled word being replaced.
+--- @return integer? # 1-based index of the chosen suggestion, or nil if cancelled.
+function M.suggest_select(items, bad)
+  return select_blocking(items, {
+    prompt = N_('Change "%s" to:'):format(bad),
+    kind = 'spell',
+    format_item = function(s)
+      local extra = s.extra and (' < "' .. s.extra .. '"') or ''
+      local score = ''
+      if vim.o.verbose > 0 then
+        score = s.altscore
+            and (' (%s%d - %d)'):format(s.salscore and 's ' or '', s.score, s.altscore)
+          or (' (%d)'):format(s.score)
+      end
+      return ('"%s"%s%s'):format(s.word, extra, score)
+    end,
+  })
+end
+
+return M

runtime/lua/vim/_core/tag.lua

@@ -0,0 +1,44 @@
+local select_blocking = require('vim._core.ui').select_blocking
+local N_ = vim.fn.gettext
+
+local M = {}
+
+--- @class vim._core.tag.Match
+--- @field tag string
+--- @field kind? string
+--- @field pri string  Priority code, e.g. "FSC" — see `:h tag-priority`.
+--- @field file string
+--- @field extra? string
+--- @field cur boolean True if this is the currently-active tagstack match.
+
+--- Called from `do_tag()` (`:tselect`, ambiguous `:tag`, etc.) to let the user
+--- pick from `matches` via |vim.ui.select()|.
+---
+--- @param items vim._core.tag.Match[] One per matching tag.
+--- @return integer? # 1-based index of the chosen tag, or nil if cancelled.
+function M.select(items)
+  local taglen = 18
+  for _, m in ipairs(items) do
+    taglen = math.max(taglen, vim.fn.strdisplaywidth(m.tag) + 2)
+  end
+
+  return select_blocking(items, {
+    prompt = N_('Type number and <Enter> (q or empty cancels):'),
+    kind = 'tag',
+    format_item = function(m)
+      local marker = m.cur and '>' or ' '
+      local kind = m.kind or ''
+      local extra = m.extra and (' ' .. m.extra) or ''
+      return ('%s %s %-4s %-' .. taglen .. 's %s%s'):format(
+        marker,
+        m.pri,
+        kind,
+        m.tag,
+        m.file,
+        extra
+      )
+    end,
+  })
+end
+
+return M

runtime/lua/vim/_core/ui.lua

@@ -0,0 +1,23 @@
+local M = {}
+
+--- Wait for |vim.ui.select()| and return the selected index. The default vim.ui.select impl
+--- (inputlist()) is synchronous, but this also handles async pickers (fzf-lua, telescope, …).
+---
+--- @param items table Items to choose from.
+--- @param opts table Forwarded to |vim.ui.select()|.
+--- @return integer? # 1-based index of the chosen item, or nil if cancelled/interrupted.
+function M.select_blocking(items, opts)
+  local choice ---@type integer?
+  local done = false
+  vim.ui.select(items, opts or {}, function(_, idx)
+    choice = idx
+    done = true
+  end)
+  -- vim.wait returns false on timeout (math.huge means never) or interrupt (-2).
+  vim.wait(math.huge, function()
+    return done
+  end)
+  return choice
+end
+
+return M

runtime/lua/vim/ui.lua

@@ -26,11 +26,11 @@ local M = vim._defer_require('vim.ui', {
 ---@field kind? string
 
 --- Prompts the user to pick from a list of items, allowing arbitrary (potentially asynchronous)
---- work until `on_choice`.
+--- work until `on_choice`. This is the standard "picker" interface, used by |z=|, |:tselect|, etc.
 ---
---- Plugins may override `vim.ui.select` to provide a custom "picker" interface; they are expected
---- to call the `format_item` and `preview_item` handlers (if any) provided by the caller. They may
---- also use the `kind` hint (if provided by the caller) to decide how to handle some items.
+--- Plugins may override `vim.ui.select` to provide a custom picker; they are expected to call the
+--- `format_item` and `preview_item` handlers (if any) provided by the caller. They may also use the
+--- `kind` hint (if provided by the caller) to decide how to handle some items.
 ---
 --- Note: the default `vim.ui.select` currently doesn't support preview.
 ---