Expand description
An easy to use REPL, ideal when there is a need to crate an ad-hoc shell.
This library provides a fast and convenient way to generate a
REPL
for your application. It comes with easy to use command! macro that
will automatically validate and parse command arguments, doing all the type
checking for you. The REPL comes with handy help messages, input validation,
hints and TAB-completion. Many REPL features can be configured.
Example
This is a basic example corresponding to examples/minimal.rs. For more examples
see the examples/ directory, which among others shows how to handle errors, access
variables outside of handler closures and how to create REPL inside REPL, inside REPL, inside…
use easy_repl::{Repl, CommandStatus, command};
let mut repl = Repl::builder()
.add("hello", command! {
"Say hello",
(name: String) => |name| {
println!("Hello {}!", name);
Ok(CommandStatus::Done)
}
})
.add("add", command! {
"Add X to Y",
(X:i32, Y:i32) => |x, y| {
println!("{} + {} = {}", x, y, x + y);
Ok(CommandStatus::Done)
}
})
.build().expect("Failed to create repl");
repl.run().expect("Critical REPL error");The generated REPL can be used as:
> hello world
Hello world!It comes with argument number checking…
> add 1
Error: wrong number of arguments: got 1, expected 2
Usage: add X:i32 Y:i32
> hello easy repl
Error: wrong number of arguments: got 2, expected 1
Usage: hello name:String
> hello "easy repl"
Hello easy repl!…and type checking!
> add 1 world
Error: failed to parse argument value 'world': invalid digit found in string
Usage: add X:i32 Y:i32It includes automatic help and quit commands. The help message is auto-generated:
> help
Available commands:
add X:i32 Y:i32 Add X to Y
hello name:String Say hello
Other commands:
help Show this help message
quit Quit replBy default user does not have to use full command names, if the command name can be resloved unambigiously (i.e. prefix matches only a single command), e.g.
> a 1 2
1 + 2 = 3but if the input is ambigious, an error will be printed with command suggestions:
> h world
Command not found: h
Candidates:
hello
help
Use 'help' to see available commands.The REPL also by default automatically implements command hints and TAB-completion (see rustyline::hint, rustyline::completion).
Re-exports
pub use anyhow;pub use command::Command;pub use command::CommandStatus;pub use command::Critical;pub use command::CriticalError;pub use repl::Repl;