commit 6b49fba8c8b97b178ddf81a9ca0c6f36c66f942f
author Girish Palya <girishji@gmail.com> Sat Jun 28 19:47:34 2025 +0200
committer Christian Brabandt <cb@256bit.org> Sat Jun 28 19:59:36 2025 +0200
tree 16c50af553a4990be73b535a12df77f061191bd4
parent 1fa3f0c215d37b3cb36f69841d5ab29ca8e0faa5

patch 9.1.1490: 'wildchar' does not work in search contexts

Problem:  'wildchar' does not work in search contexts
Solution: implement search completion when 'wildchar' is typed
          (Girish Palya).

This change enhances Vim's command-line completion by extending
'wildmode' behavior to search pattern contexts, including:

- '/' and '?' search commands
- ':s', ':g', ':v', and ':vim' commands

Completions preserve the exact regex pattern typed by the user,
appending the completed word directly to the original input. This
ensures that all regex elements — such as '<', '^', grouping brackets
'()', wildcards '\*', '.', and other special characters — remain intact
and in their original positions.

---

**Use Case**

While searching (using `/` or `?`) for lines containing a pattern like
`"foobar"`, you can now type a partial pattern (e.g., `/f`) followed by
a trigger key (`wildchar`) to open a **popup completion menu** showing
all matching words.

This offers two key benefits:

1. **Precision**: Select the exact word you're looking for without
typing it fully.
2. **Memory aid**: When you can’t recall a full function or variable
name, typing a few letters helps you visually identify and complete the
correct symbol.

---

**What’s New**

Completion is now supported in the following contexts:

- `/` and `?` search commands
- `:s`, `:g`, `:v`, and `:vimgrep` ex-commands

---

**Design Notes**

- While `'wildchar'` (usually `<Tab>`) triggers completion, you'll have
to use `<CTRL-V><Tab>` or "\t" to search for a literal tab.
- **Responsiveness**: Search remains responsive because it checks for
user input frequently.

---

**Try It Out**

Basic setup using the default `<Tab>` as the completion trigger:

```vim
set wim=noselect,full wop=pum wmnu
```

Now type:

```
/foo<Tab>
```

This opens a completion popup for matches containing "foo".
For matches beginning with "foo" type `/\<foo<Tab>`.

---

**Optional: Autocompletion**

For automatic popup menu completion as you type in search or `:`
commands, include this in your `.vimrc`:

```vim
vim9script
set wim=noselect:lastused,full wop=pum wcm=<C-@> wmnu

autocmd CmdlineChanged [:/?] CmdComplete()

def CmdComplete()
  var [cmdline, curpos, cmdmode] = [getcmdline(), getcmdpos(),
expand('<afile>') == ':']
  var trigger_char = '\%(\w\|[*/:.-]\)$'
  var not_trigger_char = '^\%(\d\|,\|+\|-\)\+$'  # Exclude numeric range
  if getchar(1, {number: true}) == 0  # Typehead is empty, no more
pasted input
      && !wildmenumode() && curpos == cmdline->len() + 1
      && (!cmdmode || (cmdline =~ trigger_char && cmdline !~
not_trigger_char))
    SkipCmdlineChanged()
    feedkeys("\<C-@>", "t")
    timer_start(0, (_) => getcmdline()->substitute('\%x00', '',
'ge')->setcmdline())  # Remove <C-@>
  endif
enddef

def SkipCmdlineChanged(key = ''): string
  set ei+=CmdlineChanged
  timer_start(0, (_) => execute('set ei-=CmdlineChanged'))
  return key == '' ? '' : ((wildmenumode() ? "\<C-E>" : '') .. key)
enddef

**Optional: Preserve history recall behavior**
cnoremap <expr> <Up> SkipCmdlineChanged("\<Up>")
cnoremap <expr> <Down> SkipCmdlineChanged("\<Down>")

**Optional: Customize popup height**
autocmd CmdlineEnter : set bo+=error | exec $'set ph={max([10,
winheight(0) - 4])}'
autocmd CmdlineEnter [/?] set bo+=error | set ph=8
autocmd CmdlineLeave [:/?] set bo-=error ph&
```

closes: #17570

Signed-off-by: Girish Palya <girishji@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>