nvim: lsp: highlight symbol under cursor

.config/nvim/lua/lsp.lua

@@ -33,6 +33,47 @@ packer.use {
             maplsp('n', '<space>ca', vim.lsp.buf.code_action)
             maplsp('n', 'gr', vim.lsp.buf.references)
             maplsp('n', '<space>f', vim.lsp.buf.formatting)
+
+            -- highlight symbol under cursor
+            if client.resolved_capabilities.document_highlight then
+                vim.cmd [[
+                hi! LspReferenceRead cterm=bold ctermbg=red guibg=#633466
+                hi! LspReferenceText cterm=bold ctermbg=red guibg=#633466
+                hi! LspReferenceWrite cterm=bold ctermbg=red guibg=#633466
+                ]]
+                vim.api.nvim_create_augroup('lsp_document_highlight', {
+                    clear = false
+                })
+                vim.api.nvim_clear_autocmds({
+                    buffer = bufnr,
+                    group = 'lsp_document_highlight',
+                })
+                vim.api.nvim_create_autocmd({ 'CursorHold', 'CursorHoldI' }, {
+                    group = 'lsp_document_highlight',
+                    buffer = bufnr,
+                    callback = vim.lsp.buf.document_highlight,
+                })
+                vim.api.nvim_create_autocmd('CursorMoved', {
+                    group = 'lsp_document_highlight',
+                    buffer = bufnr,
+                    callback = vim.lsp.buf.clear_references,
+                })
+            end
+
+            vim.api.nvim_create_autocmd("CursorHold", {
+                buffer = bufnr,
+                callback = function()
+                    local opts = {
+                        focusable = false,
+                        close_events = { "BufLeave", "CursorMoved", "InsertEnter", "FocusLost" },
+                        border = 'rounded',
+                        source = 'always',
+                        prefix = ' ',
+                        scope = 'cursor',
+                    }
+                    vim.diagnostic.open_float(nil, opts)
+                end
+            })
         end
 
         -- setup servers

.config/nvim/lua/settings.lua

@@ -13,6 +13,7 @@ vim.o.completeopt = 'menu,menuone,noselect' -- completion popup
 vim.o.autochdir = true                      -- change workir to current file dir
 vim.opt.conceallevel = 2                    -- hidden stuff, needed for org
 vim.opt.concealcursor = 'nc'
+vim.o.updatetime = 500                      -- fire CursorHold autocommand event
 
 -- theme
 vim.o.termguicolors = true                  -- 24 bit colours