1 # This file is part of NIT ( http://www.nitlanguage.org ).
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
7 # http://www.apache.org/licenses/LICENSE-2.0
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.
15 # Basic services to display a prompt
18 # Display `prompt` in the console and wait for a response
20 # Return the user response, or `null` if EOF.
22 # If `add_history`, the user response is added to the history.
23 fun prompt
(prompt
: Text, add_history
: nullable Bool): nullable String
26 var res
= stdin
.read_line
27 if res
== "" and stdin
.eof
then return null
31 # Add `line` to the shell history
33 # The default implementation is a noop, but other packages can refine it.
34 fun prompt_add_history
(line
: String) do end