rustyline VS omnomnomicon

This latest release adds a Rustyline-based REPL and additional tools for using the filesystem as a relational database. The new init subcommand lets you declare the primary key by which a directory (and its subdirectories) are indexed, while ins and del now allow insertion and deletion of records while keeping related indices up to date. ls is helpful in the REPL, showing Ghee's view of the world.

That what gnu readline is good at, interpreter like interface. There is also this one https://github.com/kkawakam/rustyline

In the process of implementing Marwood's web REPL, I ported rust's [Rustyline](https://github.com/kkawakam/rustyline) readline library to an Xterm.js typescript addon called [xterm-readline](https://github.com/strtok/xterm-readline/).

There is rustyline, which is a readline implementation. It supports line editing in emacs or vi mode (selectable). I don't know if it can operate on two strings as input, but if your program takes input from a terminal, this could be what you are looking for.

Not sure if it will help in this case (docs always take effort to write and make good), but most crates have an examples directory in the root of their repo which can be helpful in the absence of guide-level docs https://github.com/kkawakam/rustyline/tree/master/examples

https://crates.io/crates/rustyline - readline clone in Rust

https://github.com/kkawakam/rustyline (literally, input a command)

Also based on popular demand, the REPL tool now uses a slightly enhanced version of rustyline for line editing and history.

it is also worth checking if library contains examples. this one does.

Maybe try reedline or rustyline and see if they meet your needs?

https://github.com/pacak/omnomnomicon - something a bit fancier but not released yet, gives you readline + custom completing parsers.

Have your crate in dev-dependencies with all the features you want. Example: https://github.com/pacak/omnomnomicon/blob/master/Cargo.toml