MrRacket

A script to easily run Racket files created with DrRacket using the command-line Racket REPL.

What's MrRacket for?

DrRacket is the editor of choice to teach Racket following the approach of How to design programs. Unfortunately, it is also inaccessible with screenreaders; I created this simple script mrracket as a workaround.

Prerequisites

MrRacket is a Bash script, and hence it requires Bash. It has only been tested on Ubuntu Linux, since its first users will use that particular flavor of GNU/Linux.

MrRacket relies on a standard installation of Racket, which you can download here.

Installation

Download mrracket and put it in a directory in the path.

Alternatively, you can download and use the install.sh script, which will install DrRacket, add its executables directory to the path, put MrRacket into the same directory, and add a desktop launcher for DrRacket.

wget -O - https://bit.ly/mrracket | bash -l

If you need to call the installation script with some non-default options, you can pass -s to bash. For example, to activate option -o (overwrite existing installations):

wget -O - https://bit.ly/mrracket | bash -l -s -- -o

Usage

To evaluate a Racket file example.rkt created with DrRacket in one of the HtDP languages (BSL, BSL+, ISL, ISL+, and ASL):

mrracket example.rkt

This achieves something similar to clicking Run in DrRacket: it loads the definitions in example.rkt and runs any tests defined there. Afterwards, it also opens Racket's REPL prompt, which is like DrRacket's interactions area. However, the definitions in example.rkt are only available after you type:

,enter example.rkt

at the prompt.

Whenever you edit the content of example.rkt with your favorite text editor, you have to repeat the process:

• Exit the Racket environment with Ctrl+D
• Rerun mrracket example.rkt
• Type ,enter example.rkt at the prompt

Finally, you can also initialize a new Racket file new.rkt in a way that it is compatible with DrRacket's files:

mrracket -L LANGUAGE new.rkt

where LANGUAGE is one of the HtDP languages: BSL, BSL+, ISL, ISL+, ASL. This command creates a new file new.rkt, which you can edit and run with DrRacket or with MrRacket.

Other functionalities

Other functionalities of DrRacket are available through the REPL prompt. Try ,help at the prompt for a list. For example ,doc opens a browser with Racket's documentation, similar to DrRacket's Help menu.