feat: setup auto completion for neovim

.config/nvim/init.lua

@@ -15,3 +15,6 @@ require("lsp")          -- ./lua/lsp/init.lua
 require("lsp.maps")     -- ./lua/lsp/maps.lua
 require("lsp.c")        -- ./lua/lsp/c.lua
 require("lsp.python")   -- ./lua/lsp/python.lua
+
+-- auto complete
+require("plugin.compe") -- ./lua/compe.lua

.config/nvim/lua/plugin/compe.lua

@@ -0,0 +1,73 @@
+-- Author        : swytch
+-- Created       : Tuesday Mar 18, 2021 23:12:25 CET
+-- License       : GPLv3
+-- Description   : compe plugin config file
+
+require("compe").setup {
+        enabled                 = true;
+        autocomplete            = false;
+        debug                   = false;
+        min_length              = 1;
+        preselect               = "enable";
+        throttle_time           = 80;
+        source_timeout          = 200;
+        incomplete_delay        = 400;
+        max_abbr_width          = 100;
+        max_kind_width          = 10;
+        max_menu_width          = 100;
+        documentation           = true;
+
+        source = {
+                path            = {menu = "  [path]"},
+                buffer          = {menu = "  [buff]"},
+                calc            = {menu = "  [calc]"},
+                -- vsnip        = {menu = "  [snip]"},
+                nvim_lsp        = {menu = "  [LSP]"},
+                nvim_lua        = {menu = "  [nvim]"},
+                spell           = {menu = "  [spel]"},
+                tags            = false,
+                treesitter      = {menu = "  [tree]"},
+        };
+}
+
+local t = function(str)
+        return vim.api.nvim_replace_termcodes(str, true, true, true)
+end
+
+local check_back_space = function()
+        local col = vim.fn.col('.') - 1
+        if col == 0 or vim.fn.getline('.'):sub(col, col):match('%s') then
+                return true
+        else
+                return false
+        end
+end
+
+-- Use (s-)tab to:
+--- move to prev/next item in completion menuone
+--- jump to prev/next snippet's placeholder
+_G.tab_complete = function()
+        if vim.fn.pumvisible() == 1 then
+                return t "<C-n>"
+--      elseif vim.fn.call("vsnip#available", {1}) == 1 then
+--              return t "<Plug>(vsnip-expand-or-jump)"
+        elseif check_back_space() then
+                return t "<Tab>"
+        else
+                return vim.fn['compe#complete']()
+        end
+end
+_G.s_tab_complete = function()
+        if vim.fn.pumvisible() == 1 then
+                return t "<C-p>"
+--      elseif vim.fn.call("vsnip#jumpable", {-1}) == 1 then
+--              return t "<Plug>(vsnip-jump-prev)"
+        else
+                return t "<S-Tab>"
+        end
+end
+
+vim.api.nvim_set_keymap("i", "<Tab>", "v:lua.tab_complete()", {expr = true})
+vim.api.nvim_set_keymap("s", "<Tab>", "v:lua.tab_complete()", {expr = true})
+vim.api.nvim_set_keymap("i", "<S-Tab>", "v:lua.s_tab_complete()", {expr = true})
+vim.api.nvim_set_keymap("s", "<S-Tab>", "v:lua.s_tab_complete()", {expr = true})

.config/nvim/lua/plugins.lua

@@ -38,6 +38,9 @@ return require("packer").startup(function()
         -- LSP
         use "neovim/nvim-lspconfig"
 
+        -- auto completion
+        use "hrsh7th/nvim-compe"
+
         -- display colors directly in editor
         use {
                 "norcalli/nvim-colorizer.lua",

.config/nvim/lua/settings.lua

@@ -42,7 +42,7 @@ o.showmatch             = true
 o.ignorecase            = true
 o.smartcase             = true
 o.inccommand            = "split"
-o.completeopt           = "menuone,noinsert,noselect"
+o.completeopt           = "menuone,noselect"
 
 -- statusline
 o.laststatus            = 2