nvim: plugins: Drop luasnip and use snippy

Our snippet usage is not extensive. Use snippy which is a more
minimalistic plugin.

nvim/.config/nvim/after/plugin/snipcomp.lua

@@ -1,63 +0,0 @@
---[[
-  Companion plugin for the LuaSnip snippet engine. Defines a completion
-  function which can be used for built-in insert mode completion (e.g. omni
-  completion). See 'ins-completion' for details. After completion the snippet
-  is expanded.
-  https://github.com/potamides/dotfiles/blob/master/.config/nvim/plugin/snipcomp.lua
---]]
-
--- lazy load LuaSnip, only useful when LuaSnip wasn't already loaded elsewhere
-local luasnip = setmetatable({}, {__index = function(_, key) return require("luasnip")[key] end})
-vim.luasnip = {}
-
--- https://github.com/hrsh7th/nvim-cmp/issues/180#issuecomment-915405589
-require'luasnip'.config.set_config { history = true }
-require('luasnip.loaders.from_vscode').lazy_load {}
-
-local function snippet2completion(snippet)
-  return {
-    word      = snippet.trigger,
-    menu      = snippet.name,
-    info      = vim.trim(table.concat(vim.tbl_flatten({snippet.dscr or "", "", snippet:get_docstring()}), "\n")),
-    dup       = true,
-    user_data = "luasnip"
-  }
-end
-
-local function snippetfilter(line_to_cursor, base)
-  return function(s)
-    return not s.hidden and vim.startswith(s.trigger, base) and s.show_condition(line_to_cursor)
-  end
-end
-
--- Set 'completefunc' or 'omnifunc' to 'v:lua.vim.luasnip.completefunc' to get
--- completion.
-function vim.luasnip.completefunc(findstart, base)
-  local line, col = vim.api.nvim_get_current_line(), vim.api.nvim_win_get_cursor(0)[2]
-  local line_to_cursor = line:sub(1, col)
-
-  if findstart == 1 then
-    return vim.fn.match(line_to_cursor, '\\k*$')
-  end
-
-  local snippets = vim.list_extend(vim.list_slice(luasnip.get_snippets("all")), luasnip.get_snippets(vim.bo.filetype))
-  snippets = vim.tbl_filter(snippetfilter(line_to_cursor, base), snippets)
-  snippets = vim.tbl_map(snippet2completion, snippets)
-  table.sort(snippets, function(s1, s2) return s1.word < s2.word end)
-  return snippets
-end
-
-function vim.luasnip.completion_expand(item)
-  if item.user_data == "luasnip" and luasnip.expandable() then
-    luasnip.expand()
-  end
-end
-
-vim.cmd([[
-  augroup luasnip_completion_expand
-    autocmd!
-    autocmd CompleteDone * call v:lua.vim.luasnip.completion_expand(v:completed_item)
-  augroup END
-]])
-
-vim.o.completefunc = 'v:lua.vim.luasnip.completefunc'

nvim/.config/nvim/after/plugin/snippy.lua

@@ -0,0 +1,19 @@
+local snippy_id = vim.api.nvim_create_augroup("snippy", { clear = true })
+
+vim.api.nvim_create_autocmd("CompleteDone", {
+  group    = snippy_id,
+  callback = function()
+    require("snippy").complete_done()
+  end,
+})
+
+require("snippy").setup({
+  mappings = {
+    is = {
+      ["<tab>"]   = "next",
+      ["<s-tab>"] = "previous",
+    },
+  },
+})
+
+vim.keymap.set('i', '<C-x><C-u>', '<cmd>lua require(\'snippy\').complete()<CR>', { noremap = true, unique = true, silent = true })

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

@@ -16,9 +16,9 @@ local init = function ()
   use 'rmagatti/auto-session'
   -- Snippets
   use {
-    'L3MON4D3/LuaSnip',
+    'dcampos/nvim-snippy',
     requires = {
-      'rafamadriz/friendly-snippets',
+      'honza/vim-snippets',
     }
   }
   -- Git support