nvim: lsp/plugins: Add support for automatically showing fn signature

nvim/.config/nvim/lua/lsp.lua

@@ -1,5 +1,6 @@
 local nvim_lsp   = require('lspconfig')
 local protocol   = require('vim.lsp.protocol')
+local signature  = require('lsp_signature')
 
 -- Taken from https://www.reddit.com/r/neovim/comments/gyb077/nvimlsp_peek_defination_javascript_ttserver/
 function preview_location(location, context, before_context)
@@ -44,6 +45,14 @@ function peek_definition()
 end
 
 local on_attach = function(client, bufnr)
+  signature.on_attach({
+    bind         = true,
+    hint_enable  = true,
+    hint_prefix  = "🐼 ",
+    hint_scheme  = "String",
+    handler_opts = { border = "single" },
+    decorator    = {"`", "`"}
+  })
   vim.api.nvim_buf_set_option(bufnr, 'omnifunc', 'v:lua.vim.lsp.omnifunc')
 
   if client.config.flags then
@@ -58,7 +67,6 @@ local on_attach = function(client, bufnr)
   vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gr', '<cmd>lua vim.lsp.buf.references()<CR>', opts)
   vim.api.nvim_buf_set_keymap(bufnr, 'n', 'ga', '<cmd>lua vim.lsp.buf.code_action()<CR>', opts)
   vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gi', '<cmd>lua vim.lsp.buf.implementation()<CR>', opts)
-  vim.api.nvim_buf_set_keymap(bufnr, 'n', 'gs', '<cmd>lua vim.lsp.buf.signature_help()<CR>', opts)
   vim.api.nvim_buf_set_keymap(bufnr, 'n', '<C-k>', '<cmd>lua vim.lsp.buf.type_definition()<CR>', opts)
   vim.api.nvim_buf_set_keymap(bufnr, 'n', '1gd', '<cmd>lua vim.lsp.buf.document_symbol()<CR>', opts)
   vim.api.nvim_buf_set_keymap(bufnr, 'n', '1gD', '<cmd>lua vim.lsp.buf.workspace_symbol()<CR>', opts)

nvim/.config/nvim/lua/plugins.lua

@@ -113,6 +113,7 @@ local init = function ()
   -- LSP
   use {
     'neovim/nvim-lspconfig',
+    'ray-x/lsp_signature.nvim'
   }
   -- Language support & syntax highlighting
   -- Haskell