speed up :LspInstall, :LspUninstall, :LspUninstallAll commands (#175)

- `:LspUninstallAll` now just nukes the entire install directory immediately,
  instead of uninstalling each server one by one. There's also a confirmation
  prompt now.
- `:LspInstall` & `:LspUninstall` now sources its autocompletion directly from
  a Lua table, instead of sourcing the server names from each server module (thus
  avoiding unnecessary `require` calls).

1 files changed, 22 insertions, 11 deletions

diff --git a/lua/nvim-lsp-installer/servers/init.lua b/lua/nvim-lsp-installer/servers/init.lua
index 64359520..94a67b3c 100644
--- a/lua/nvim-lsp-installer/servers/init.lua
+++ b/lua/nvim-lsp-installer/servers/init.lua
@@ -176,10 +176,6 @@ function M.get_server(server_name)
         ):format(server_name, "https://github.com/williamboman/nvim-lsp-installer", server_factory)
 end
 
-local function get_available_server_names()
-    return vim.tbl_keys(vim.tbl_extend("force", CORE_SERVERS, INITIALIZED_SERVERS))
-end
-
 local function resolve_servers(server_names)
     return Data.list_map(function(server_name)
         local ok, server = M.get_server(server_name)
@@ -190,20 +186,35 @@ local function resolve_servers(server_names)
     end, server_names)
 end
 
+function M.get_available_server_names()
+    return vim.tbl_keys(vim.tbl_extend("force", CORE_SERVERS, INITIALIZED_SERVERS))
+end
+
+function M.get_installed_server_names()
+    return vim.tbl_filter(function(server_name)
+        return M.is_server_installed(server_name)
+    end, M.get_available_server_names())
+end
+
+function M.get_uninstalled_server_names()
+    return vim.tbl_filter(function(server_name)
+        return not M.is_server_installed(server_name)
+    end, M.get_available_server_names())
+end
+
+-- Expensive to call the first time - loads all server modules.
 function M.get_available_servers()
-    return resolve_servers(get_available_server_names())
+    return resolve_servers(M.get_available_server_names())
 end
 
+-- Somewhat expensive to call the first time (depends on how many servers are currently installed).
 function M.get_installed_servers()
-    return resolve_servers(vim.tbl_filter(function(server_name)
-        return M.is_server_installed(server_name)
-    end, get_available_server_names()))
+    return resolve_servers(M.get_installed_server_names())
 end
 
+-- Expensive to call the first time (depends on how many servers are currently not installed).
 function M.get_uninstalled_servers()
-    return resolve_servers(vim.tbl_filter(function(server_name)
-        return not M.is_server_installed(server_name)
-    end, get_available_server_names()))
+    return resolve_servers(M.get_uninstalled_server_names())
 end
 
 function M.register(server)