lib/prompt.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 # Basic services to display a prompt
  16 module prompt
  17
  18 # Display `prompt` in the console and wait for a response
  19 #
  20 # Return the user response, or `null` if EOF.
  21 #
  22 # If `add_history`, the user response is added to the history.
  23 fun prompt(prompt: Text, add_history: nullable Bool): nullable String
  24 do
  25         printn prompt
  26         var res = stdin.read_line
  27         if res == "" and stdin.eof then return null
  28         return res
  29 end
  30
  31 # Add `line` to the shell history
  32 #
  33 # The default implementation is a noop, but other packages can refine it.
  34 fun prompt_add_history(line: String) do end