nvim: proper move to lua

vim/.config/nvim/lua/plugins/luasnip.lua

@@ -0,0 +1,57 @@
+-- TODO: figure out how to simplify the snippets config
+-- TODO: figure out how to create custom snippets
+-- TODO: is it possible to use luasnip without nvim-cpm?
+
+local function prequire(...)
+local status, lib = pcall(require, ...)
+if (status) then return lib end
+    return nil
+end
+
+local luasnip = prequire('luasnip')
+local cmp = prequire("cmp")
+
+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
+
+_G.tab_complete = function()
+    if cmp and cmp.visible() then
+        cmp.select_next_item()
+    elseif luasnip and luasnip.expand_or_jumpable() then
+        return t("<Plug>luasnip-expand-or-jump")
+    elseif check_back_space() then
+        return t "<Tab>"
+    else
+        cmp.complete()
+    end
+    return ""
+end
+_G.s_tab_complete = function()
+    if cmp and cmp.visible() then
+        cmp.select_prev_item()
+    elseif luasnip and luasnip.jumpable(-1) then
+        return t("<Plug>luasnip-jump-prev")
+    else
+        return t "<S-Tab>"
+    end
+    return ""
+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})
+vim.api.nvim_set_keymap("i", "<C-E>", "<Plug>luasnip-next-choice", {})
+vim.api.nvim_set_keymap("s", "<C-E>", "<Plug>luasnip-next-choice", {})
+
+require("luasnip.loaders.from_vscode").lazy_load()