Haskell Extension for Visual Studio Code starts a new Haskell Language Server for each file

Question

I recently installed the Haskell extension in Visual Studio Code which is powered by the Haskell Language Server. Each time I open a different Haskell file in the editor a new process named "haskell-language-server-1.0.0-linux-8.6.5" is created. The result of this is that each time I hover over a word in my program I see everything, like types or errors written two times. More important each of these processes consumes about 1 Gb of RAM and eventually my system crashes. Is there anything I could do to avoid all of this?

Answer 1

I encountered The same problem.

To solve this problem, I opened the folder containing all wanted files, i.e.,File -> Open Folder. This solution is sufficient if you have all wanted files located within a single folder. This folder can contain other folders that also contain haskell files (or any similiar recursive file structure), and still only one language server will be created

If you want to use files that are located in different folders, there are two options depending on how many language servers you are willing to tolerate:

1. Single Language Server: Move all folders containing wanted files to a new folder; as visual studio code views this as a single folder, only a single language server is spawned.
2. Specific Limit of Language Servers: Create a workspace and add folders containing wanted files to it. More specifically: a) Close any current workspace, folder, or file( these actions can be found at the bottom of the file menu), b) add wanted folders to workspace by File->Add Folder to Workspace, c)(optional) If you want to use such a setup in the future you can save this workspace by File -> Save WorkSpace as. Each added folder that is added directly through the Add folder to Workspace action will spawn a new language server;it is the number of folders opened this way that determines the amount, not the total amount of folders open.