Setting up Go to definition?

[MarcCoquand]

Hi!

I can't really understand how I am supposed to use the go to definition functionality. Using gd does not seem to work. The documentation only mentions that it's possible, but not how to set it up.

[mrcjkb]

Hey,

if you want to map gd to go-to-definition, you can add a keymap:

opts = { noremap = true, silent = true, buffer = bufnr } -- bufnr is an argument of the on_attach function
vim.keymap.set('n', 'gd', vim.lsp.buf.definition, opts)

I don't include all LSP-related keymaps in the readme, because there are already a bunch of suggestions in the nvim-lspconfig readme (which I link to).

For go-to-definition specifically, neovim automatically sets up a tagfunc, so you can use C-[ to jump to a definition, and fall back to tags if the definition can't be found. This is useful if you also use something like fast-tags.

[MarcCoquand]

Ah, I have that set up, but I didn't need to explicitly set it for other languages. It seems to work now when I added it to my ftplugin/haskell file.

[mrcjkb]

Great to hear you were able to solve it 😄

I guess for the other languages, you had it set in the on_attach function?

[MarcCoquand]

Yeah exactly, and it seems to haskell-tools has a separate procedure for how it attaches?

Thank you so much for the support :)

[mrcjkb]

Both haskell-tools and nvim-lspconfig use vim.lsp.start() under the hood, so it's the same procedure.
But nvim-lspconfig sets up autocommands for filetypes, in order to detect when to attach which LSP client.
haskell-tools can do that, too (with the setup() function), but I recommend to use setup_or_attach() in a ftplugin/haskell.lua file, because setting up autocommands slows down Neovim's startup performance.

haskell-tools won't use anything from nvim-lspconfig, unless you explicitly pass it into the on_attach callback.