haskell-tools.nvim 1.9.0 - Minimising the impact on Neovim's startup footprint with ftplugin support

[mrcjkb]

For language-specific plugins like this one, it can make sense to load them only when actually working with the respective language.
For this reason, I have added support for setting up haskell-tools.nvim in ~/.config/nvim/ftplugin/haskell.lua.

local ht = require('haskell-tools')
ht.start_or_attach {
  -- the config is cached
}

local bufnr = vim.api.nvim_get_current_buf()
local opts = { noremap = true, silent = true, buffer = bufnr }
vim.keymap.set('n', '<space>ca', vim.lsp.codelens.run, opts)
vim.keymap.set('n', '<space>hs', ht.hoogle.hoogle_signature, opts)
vim.keymap.set('n', '<space>ea', ht.lsp.buf_eval_all, opts)
vim.keymap.set('n', '<leader>rr', ht.repl.toggle, opts)
-- ...

I have made it backward compatible, so existing configurations that use ht.setup {} won't break.

If you want to migrate, simply move your haskell-tools.nvim setup code to ~/.config/nvim/ftplugin/haskell.lua (the path may be different if you are using a different Neovim distribution) and replace the call to setup with start_or_attach.

Both functions take exactly the same table as an argument.

The differences

setup

• Creates filetype autocommands that are redundant if called from ftplugin/haskell.lua.
• Validates and sets the config every time it is called.

start_or_attach

• Doesn't create any filetype autocommands.
• Caches the config (only validates and sets it on the first call).
• Subsequent calls will only start or attach an LSP client, generate tags, etc.

Note

If you want to use haskell-language-server with .cabal files,
you can extract the setup code to a shared module and call it in both ftplugin/haskell.lua and ftplugin/cabal.lua.

Here is an example from my personal dotfiles.

Other

• lsp.buf_eval_all has been stabilised with this release