feat: add cached_list

Use a `locate` command instead of `fd`, to get cached results. Update
the documentation as well.

Fixes #3

Author: cljoly

README.md

@@ -80,9 +80,12 @@ use {
 
 ### Required
 
-* [`fd`][] to find the repositories on the filesystem
+* [`fd`][] to find the repositories on the filesystem with `list`
+* [`plocate`][] or [`locate`][] to find the repositories on the filesystem with `cached_list`
 
 [`fd`]: https://github.com/sharkdp/fd
+[`locate`]: https://man.archlinux.org/man/locate.1
+[`plocate`]: https://man.archlinux.org/man/plocate.1
 
 ### Optional
 
@@ -173,9 +176,52 @@ Here is how you can use this plugin with various SCM:
 
 Is your favorite SCM missing? It should be straightforward to support it by changing the pattern parameter. If you want it to be considered for addition here, open a PR!
 
+### cached_list
+
+`:Telescope repo cached_list`
+
+This relies on a `locate` command to find repositories. This should be much faster than the `list` command, as it relies on a pre-built index but results may be stalled.
+
+*Note*: at this point, the plugin does not manage index update. Updating the index often requires to run a command like `updatedb` as root.
+
+#### Troubleshooting
+
+You should try to run:
+```
+sudo updatedb
+```
+if you encounter any problems. If it’s not the case by default, you should automate such index update with for instance `cron` or `systemd-timers`. See https://wiki.archlinux.org/title/Locate.
+
+#### Options
+
+Options are the similar to `repo list`, bearing in mind that we use `locate` instead of `fd`. Note that:
+
+* `fd_opts` is not supported, as we don’t use `fd`
+
+#### Examples
+
+##### Exclude Irrelevant Results
+
+Chances are you will get results from folders you don’t care about like `.cache` or `.cargo`. In that case, you can use the `file_ignore_patterns` option of Telescope, like so (these are lua regexes):
+
+```
+:lua require'telescope'.extensions.repo.cached_list{file_ignore_patterns={'.cache/', '.cargo/'}}
+```
+
+##### Use With Other SCMs
+
+Here is how you can use this plugin with various SCM (we match on the whole path with `locate`, so patterns differ slightly from `repo list`: notice the `^` that becomes a `/`):
+
+| SCM    | Command                                                                    |
+|--------|----------------------------------------------------------------------------|
+| git    | `:Telescope repo list` or `lua require'telescope'.extensions.repo.list{}`  |
+| pijul  | `lua require'telescope'.extensions.repo.list{pattern=[[/\.pijul$]]}`       |
+| hg     | `lua require'telescope'.extensions.repo.list{pattern=[[/\.hg$]]}`          |
+| fossil | `lua require'telescope'.extensions.repo.list{pattern=[[/\.fslckout$]]}`    |
+
 ## FAQ
 
 ### Getting the repository list is slow
 
-You can use your `.fdignore` to exclude some folders from your filesystem. If there is enough interest, [#1](https://github.com/cljoly/telescope-repo.nvim/issues/1) could further enhance this.
+If `:Telescope repo list` is slow, you can use your `.fdignore` to exclude some folders from your filesystem. If there is enough interest, [#1](https://github.com/cljoly/telescope-repo.nvim/issues/1) could further enhance this.
 

lua/telescope/_extensions/repo.lua

@@ -2,6 +2,7 @@ local repo_builtin = require'telescope._extensions.repo_builtin'
 
 return require'telescope'.register_extension{
   exports = {
-    list = repo_builtin.list
+    list = repo_builtin.list,
+    cached_list = repo_builtin.cached_list,
   },
 }

lua/telescope/_extensions/repo_builtin.lua

@@ -125,6 +125,28 @@ local function call_picker(opts, command)
   }):find()
 end
 
+-- List of repos built using locate (or variants)
+M.cached_list = function(opts)
+  opts = opts or {}
+  opts.cwd = vim.env.HOME
+  opts.bin = opts.bin and vim.fn.expand(opts.bin) or nil
+  -- Use alternative locate if possible
+  if opts.bin == nil then
+    if vim.fn.executable'plocate' == 1 then
+      opts.bin = 'plocate'
+    elseif vim.fn.executable'locate' == 1 then -- Fallback
+      opts.bin = 'locate'
+    else
+      error "Please install locate (or one of its alternatives)"
+    end
+  end
+  local bin = vim.fn.expand(opts.bin)
+
+  local repo_pattern = opts.pattern or [[/\.git$]] -- We match on the whole path
+  local locate_command = {bin, '-r', repo_pattern}
+  call_picker(opts, locate_command)
+end
+
 -- Always up to date list of repos built using fd
 M.list = function(opts)
   opts = opts or {}