add a cool lua repl

lib/lua-repl/repl/plugins/rcfile.lua

@@ -0,0 +1,54 @@
+-- Copyright (c) 2011-2015 Rob Hoelz <rob@hoelz.ro>
+--
+-- Permission is hereby granted, free of charge, to any person obtaining a copy of
+-- this software and associated documentation files (the "Software"), to deal in
+-- the Software without restriction, including without limitation the rights to
+-- use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+-- the Software, and to permit persons to whom the Software is furnished to do so,
+-- subject to the following conditions:
+--
+-- The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+-- FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+-- COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+-- IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+-- CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+-- A plugin that runs code in $HOME/.rep.lua before the REPL starts
+
+local setfenv = require('repl.utils').setfenv
+
+local function readable(filename)
+  local f = io.open(filename, 'r')
+  if not f then
+    return false
+  end
+  f:close()
+  return true
+end
+
+local function init()
+  local home = os.getenv 'HOME'
+
+  if not home then
+    return
+  end
+
+  local rcfile = home .. '/.rep.lua'
+
+  if not readable(rcfile) then
+    return
+  end
+
+  local chunk = assert(loadfile(rcfile))
+  local env   = setmetatable({ repl = repl }, { __index = _G, __newindex = _G })
+
+  setfenv(chunk, env)
+
+  chunk()
+  return true
+end
+
+return init()