feat(julials): Better configurability for LanguageServer.jl install l…

…ocation.

lua/lspconfig/julials.lua

@@ -7,9 +7,17 @@ local cmd = {
   '--history-file=no',
   '-e',
   [[
-    using Pkg
-    Pkg.instantiate()
-    using LanguageServer
+    # Load LanguageServer.jl
+    if length(ARGS) > 0
+        # If there is an argument, use this as the load path for finding
+        # the installation of LanguageServer.jl
+        old_load_path = copy(LOAD_PATH)
+        push!(empty!(LOAD_PATH), expanduser(ARGS[1]))
+        using LanguageServer
+        append!(empty!(LOAD_PATH), old_load_path)
+    else
+        using LanguageServer
+    end
     depot_path = get(ENV, "JULIA_DEPOT_PATH", "")
     project_path = let
         dirname(something(
@@ -38,9 +46,6 @@ local cmd = {
 configs.julials = {
   default_config = {
     cmd = cmd,
-    on_new_config = function(new_config, root_dir)
-      new_config.cmd_cwd = root_dir
-    end,
     filetypes = { 'julia' },
     root_dir = function(fname)
       return util.find_git_ancestor(fname) or util.path.dirname(fname)
@@ -51,13 +56,31 @@ configs.julials = {
     description = [[
 https://github.com/julia-vscode/julia-vscode
 
-`LanguageServer.jl` can be installed with `julia` and `Pkg`:
+LanguageServer.jl can be installed with `julia` and `Pkg`:
+```sh
+julia -e 'using Pkg; Pkg.add("LanguageServer")'
+```
+This installs LanguageServer.jl into your global julia environment where the default launch
+command will look for the package.
+
+It is possible to use a separate package environment for the LanguageServer.jl installation.
+For example, to install in a folder `~/.local/share/nvim/lspconfig/julia-ls` use the following command:
 ```sh
-julia -e 'using Pkg; Pkg.add("LanguageServer"); Pkg.add("SymbolServer")'
+julia --project=~/.local/share/nvim/lspconfig/julia-ls -e 'using Pkg; Pkg.add("LanguageServer")'
+```
+and modify the language server launch command accordingly in your init file, e.g.
+```lua
+require'lspconfig'.julials.setup{
+    on_new_config = function(new_config, _)
+        -- Default cmd takes one optional argument, so push the custom LanguageServer.jl
+        -- install location to that table
+        table.insert(new_config.cmd, "~/.local/share/nvim/lspconfig/julia-ls")
+    end,
+}
 ```
-This installs LanguageServer.jl into your global julia environment.
 
-In order to have LanguageServer.jl pick up installed packages or dependencies in a Julia project, you must first instantiate the project:
+Note: In order to have LanguageServer.jl pick up installed packages or dependencies in a
+Julia project, you must make sure that the project is instantiated:
 ```sh
 julia --project=/path/to/my/project -e 'using Pkg; Pkg.instantiate()'
 ```