feat: combine pickers (#1879)

Combine a list of pickers, first picker opts will determine
the settings (window, previewer, etc), althought we can combine
any number of pickers beware of combining pickers with wrong type
of previewers as they may not work or worse, raise an exception.

```lua
:FzfLua combine pickers=buffers,files
```

Author: ibhagwan

lua/fzf-lua/core.lua

@@ -197,11 +197,11 @@ end
 
 ---@param contents string?
 ---@param opts table
----@return thread
+---@return thread, string, table
 M.fzf_wrap = function(contents, opts)
   opts = opts or {}
   local _co
-  coroutine.wrap(function()
+  local wrapped = coroutine.wrap(function()
     _co = coroutine.running()
     if type(opts.cb_co) == "function" then opts.cb_co(_co) end
     -- Default fzf exit callback acts upon the selected items
@@ -217,8 +217,13 @@ M.fzf_wrap = function(contents, opts)
       return
     end
     utils.err("fn_selected threw an error: " .. debug.traceback(err, 1))
-  end)()
-  return _co
+  end)
+  -- Do not strt fzf, return the stringified contents and opts onlu
+  -- used by the "combine" picker to merge inputs
+  if opts._start ~= false then
+    wrapped()
+  end
+  return _co, contents, opts
 end
 
 -- conditionally update the context if fzf-lua

lua/fzf-lua/init.lua

@@ -287,7 +287,8 @@ do
     register_ui_select = { "fzf-lua.providers.ui_select", "register" },
     deregister_ui_select = { "fzf-lua.providers.ui_select", "deregister" },
     tmux_buffers = { "fzf-lua.providers.tmux", "buffers" },
-    profiles = { "fzf-lua.providers.module", "profiles" },
+    profiles = { "fzf-lua.providers.meta", "profiles" },
+    combine = { "fzf-lua.providers.meta", "combine" },
     complete_path = { "fzf-lua.complete", "path" },
     complete_file = { "fzf-lua.complete", "file" },
     complete_line = { "fzf-lua.complete", "line" },
@@ -403,7 +404,7 @@ M.builtin = function(opts)
   if not opts then return end
   opts.metatable = M
   opts.metatable_exclude = M._excluded_metamap
-  return require "fzf-lua.providers.module".metatable(opts)
+  return require "fzf-lua.providers.meta".metatable(opts)
 end
 
 return M

lua/fzf-lua/providers/buffers.lua

@@ -214,7 +214,7 @@ M.buffers = function(opts)
   opts = core.set_header(opts, opts.headers or { "actions", "cwd" })
   opts = opts.filename_only and opts or core.set_fzf_field_index(opts)
 
-  core.fzf_exec(contents, opts)
+  return core.fzf_exec(contents, opts)
 end
 
 M.lines = function(opts)
@@ -352,7 +352,7 @@ M.buffer_lines = function(opts)
   end
 
   opts = core.set_fzf_field_index(opts, "{3}", opts._is_skim and "{}" or "{..-2}")
-  core.fzf_exec(contents, opts)
+  return core.fzf_exec(contents, opts)
 end
 
 M.tabs = function(opts)
@@ -466,7 +466,7 @@ M.tabs = function(opts)
   opts = core.set_header(opts, opts.headers or { "actions", "cwd" })
   opts = opts.filename_only and opts or core.set_fzf_field_index(opts, "{4}", "{}")
 
-  core.fzf_exec(contents, opts)
+  return core.fzf_exec(contents, opts)
 end
 
 
@@ -600,7 +600,7 @@ M.treesitter = function(opts)
 
   opts = core.set_header(opts, opts.headers or { "actions" })
 
-  core.fzf_exec(contents, opts)
+  return core.fzf_exec(contents, opts)
 end
 
 M.spellcheck = function(opts)
@@ -703,7 +703,7 @@ M.spellcheck = function(opts)
 
   opts = core.set_header(opts, opts.headers or { "actions" })
 
-  core.fzf_exec(contents, opts)
+  return core.fzf_exec(contents, opts)
 end
 
 return M

lua/fzf-lua/providers/colorschemes.lua

@@ -82,7 +82,7 @@ M.colorschemes = function(opts)
     utils.setup_highlights()
   end
 
-  core.fzf_exec(colors, opts)
+  return core.fzf_exec(colors, opts)
 end
 
 M.highlights = function(opts)
@@ -137,7 +137,7 @@ M.highlights = function(opts)
     end
   end
 
-  core.fzf_exec(contents, opts)
+  return core.fzf_exec(contents, opts)
 end
 
 

lua/fzf-lua/providers/dap.lua

@@ -40,7 +40,7 @@ M.commands = function(opts)
     end,
   }
 
-  core.fzf_exec(entries, opts)
+  return core.fzf_exec(entries, opts)
 end
 
 M.configurations = function(opts)
@@ -73,7 +73,7 @@ M.configurations = function(opts)
     end,
   }
 
-  core.fzf_exec(entries, opts)
+  return core.fzf_exec(entries, opts)
 end
 
 M.breakpoints = function(opts)
@@ -116,7 +116,7 @@ M.breakpoints = function(opts)
   opts = core.set_header(opts, opts.headers or { "actions", "cwd" })
   opts = core.set_fzf_field_index(opts, "{3}", opts._is_skim and "{}" or "{..-2}")
 
-  core.fzf_exec(contents, opts)
+  return core.fzf_exec(contents, opts)
 end
 
 M.variables = function(opts)
@@ -147,7 +147,7 @@ M.variables = function(opts)
     end
   end
 
-  core.fzf_exec(entries, opts)
+  return core.fzf_exec(entries, opts)
 end
 
 M.frames = function(opts)
@@ -238,7 +238,7 @@ M.frames = function(opts)
     ))
   end
 
-  core.fzf_exec(entries, opts)
+  return core.fzf_exec(entries, opts)
 end
 
 return M

lua/fzf-lua/providers/git.lua

@@ -59,7 +59,7 @@ local function git_cmd(opts)
   opts = set_git_cwd_args(opts)
   if not opts.cwd then return end
   opts = core.set_header(opts, opts.headers or { "cwd" })
-  core.fzf_exec(opts.cmd, opts)
+  return core.fzf_exec(opts.cmd, opts)
 end
 
 local function git_preview(opts, file)

lua/fzf-lua/providers/grep.lua

@@ -206,7 +206,7 @@ M.grep = function(opts)
   opts = core.set_title_flags(opts, { "cmd" })
   opts = core.set_header(opts, opts.headers or { "actions", "cwd", "search" })
   opts = core.set_fzf_field_index(opts)
-  core.fzf_exec(opts.cmd, opts)
+  return core.fzf_exec(opts.cmd, opts)
 end
 
 local function normalize_live_grep_opts(opts)

lua/fzf-lua/providers/helptags.lua

@@ -99,7 +99,7 @@ M.helptags = function(opts)
     end)()
   end
 
-  core.fzf_exec(contents, opts)
+  return core.fzf_exec(contents, opts)
 end
 
 return M

lua/fzf-lua/providers/manpages.lua

@@ -41,7 +41,7 @@ M.manpages = function(opts)
     return string.format("%-45s %s", man, desc)
   end
 
-  core.fzf_exec(opts.cmd, opts)
+  return core.fzf_exec(opts.cmd, opts)
 end
 
 return M

lua/fzf-lua/providers/module.lua lua/fzf-lua/providers/meta.lualua/fzf-lua/providers/module.lua renamed to lua/fzf-lua/providers/meta.lua

@@ -31,7 +31,7 @@ M.metatable = function(opts)
   -- as the behavior might confuse users (#267)
   opts.no_resume = true
 
-  core.fzf_exec(methods, opts)
+  return core.fzf_exec(methods, opts)
 end
 
 ---@param dir string
@@ -97,4 +97,55 @@ M.profiles = function(opts)
   return core.fzf_exec(contents, opts)
 end
 
+M.combine = function(t)
+  t = t or {}
+  t.pickers = type(t.pickers) == "table" and type(t.pickers)
+      or type(t.pickers) == "string" and utils.strsplit(t.pickers, "[,;]")
+      or nil
+
+  -- First picker options set the tone
+  local opts1 = (function()
+    if t.pickers[1] then
+      local ok, opts = pcall(config.normalize_opts, t, t.pickers[1])
+      if not ok or not opts then
+        utils.warn("Must specify at least one valid picker")
+      else
+        return opts
+      end
+    end
+  end)()
+  if not opts1 then return end
+
+  -- Let fzf_wrap know to NOT start the coroutine
+  opts1._start = false
+
+  local cmds, opts = (function()
+    local ret, opts = {}, nil
+    for i, p in ipairs(t.pickers) do
+      -- local ok, msg, cmd, o = pcall(FzfLua[p], opts1)
+      -- if not ok or not cmd then
+      local _, cmd, o = FzfLua[p](opts1)
+      if not cmd or not o then
+        -- utils.warn(string.format("Error loading picker '%s', ignoring.\nError: %s", p, msg))
+        utils.warn(string.format("Error loading picker '%s', ignoring.", p))
+      else
+        table.insert(ret, cmd)
+        -- NOTE: we use the [first picker] modified opts after picker setup
+        -- as pickers can modify opts / add important parts (fn_pre_fzf, etc)
+        if not opts then opts = o end
+      end
+    end
+    return ret, opts
+  end)()
+  if not opts then return end
+
+  -- Let fzf_wrap know to START the coroutine
+  opts._start = nil
+
+  -- _G.dump(cmds)
+  local contents = table.concat(cmds, utils.__IS_WINDOWS and "&" or ";")
+
+  return core.fzf_wrap(contents, opts)
+end
+
 return M