Readline interface: Difference between revisions

=={{header|D}}==

<lang>module readline_interface;

import std.stdio;

import std.string;

alias VOIDF = void function();

void hello() {

writeln("Hello World!");

histArr ~= __FUNCTION__;

}

string[] histArr;

void hist() {

if (histArr.length == 0) {

writeln("No history");

} else {

foreach(cmd; histArr) {

writeln(" - ", cmd);

}

}

histArr ~= __FUNCTION__;

}

void help() {

writeln("Available commands:");

writeln(" hello");

writeln(" hist");

writeln(" exit");

writeln(" help");

histArr ~= __FUNCTION__;

}

void main() {

VOIDF[string] aa;

aa["help"] = &help;

aa["hist"] = &hist;

aa["hello"] = &hello;

writeln("Enter a command, type help for a listing.");

string line;

write(">");

while ((line = readln()) !is null) {

line = chomp(line);

if (line == "exit") {

break;

}

aa.get(line, &help)();

write(">");

}

}</lang>

{{out}}

<pre>Enter a command, type help for a listing.

>hist

No history

>help

Available commands:

hello

hist

exit

help

>hello

Hello World!

>hist

- readline_interface.hist

- readline_interface.help

- readline_interface.hello

>exit</pre>