core :: union_find
union–find algorithm using an efficient disjoint-set data structure
# Basic services to display a prompt
module prompt
# Display `prompt` in the console and wait for a response
#
# Return the user response, or `null` if EOF.
#
# If `add_history`, the user response is added to the history.
fun prompt(prompt: Text, add_history: nullable Bool): nullable String
do
printn prompt
var res = stdin.read_line
if res == "" and stdin.eof then return null
return res
end
# Add `line` to the shell history
#
# The default implementation is a noop, but other packages can refine it.
fun prompt_add_history(line: String) do end
lib/prompt/prompt.nit:15,1--34,43