How to add readline support in polyml interpreter?

The simplest way to add readline support to a terminal program that does not natively support it, is to call the program using rlwrap. You can install the package of the same name through several package managers. Pressing ↑ in the examples below:

$ poly
Poly/ML 5.7.1 Release
- ^[[A

You can run it like this:

$ rlwrap poly
Poly/ML 5.7.1 Release
- stuff I typed from last session;

Or you can add an alias in your ~/.bashrc or similar:

alias poly='rlwrap poly'

The following two QA answers your question, though for sml/nj. It should not be any different for polyml

• Conque SML backspace
• How to 'fix' the SML/NJ interactive system to use Arrow Keys