Official haskell ide support via language server (LSP).
The haskell-language-server (HLS) project is an implementation of a server (a "language server") for the Language Server Protocol (LSP). A language server talks to a client (typically an editor), which can ask the server to perform various operations, such as reporting errors or providing code completions. The advantage of this system is that clients and servers can interoperate more easily so long as they all speak the LSP protocol. In the case of HLS, that means that it can be used with many different editors, since editor support for the LSP protocol is now widespread.
The haskell-language-server (HLS) project is an implementation of a server (a "language server") for the Language Server Protocol (LSP). A language server talks to a client (typically an editor), which can ask the server to perform various operations, such as reporting errors or providing code completions. The advantage of this system is that clients and servers can interoperate more easily so long as they all speak the LSP protocol. In the case of HLS, that means that it can be used with many different editors, since editor support for the LSP protocol is now widespread.
To install haskell-language-server, run the following command in macOS terminal (Applications->Utilities->Terminal)
sudo port install haskell-language-server
To see what files were installed by haskell-language-server, run:
port contents haskell-language-server
To later upgrade haskell-language-server, run:
sudo port selfupdate && sudo port upgrade haskell-language-server
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