GRASP: The GRAphical Scheme Programming Environment

This is the repository of the GRASP project, which is intended to be an extensible editor of s-expressions optimized for interacting via touch screen.

GRASP is still work in progress, and isn’t yet mature enough to perform even the most basic editing tasks (but each day this moment is getting closer).

If you’d like to see a more detailed explanation, you may want to watch a demo.

GRASP comes in three flavours: an Android client,

a desktop client

and a terminal client

Building

In order to be built, GRASP requires a Java Runtime Environment and a POSIX shell. All the other dependencies are included in the libs directory.

Once both these requirements are met, GRASP can be built by typing

./build.scm

in the repository’s main directory. By default, the script will build all three clients (android, terminal and desktop), and the resulting jar/apk files will be contained in the build directory. The generated files contain all the required dependencies.

The particular targets can be selected by passing the --targets argument, followed by a comma-separated list of desired targets.

To get a list of all possible options, you can type

./build.scm --help

In particular, the --init option can be used to pass in the init file, which is executed during GRASP’s startup. (In case of the .jar packages, this file can also be later replaced/edited in the archives.)

Running the desktop/terminal client directly from source

Both terminal and desktop clients can be run without (explicit) compilation. This can be achieved by typing

./grasp-terminal

to run the terminal client, or

./grasp-desktop

to run the desktop client. This way of running the project is not recommended, except for the purpose of development.

Debugging the Android client

Some builds of Android are capable of printing complete stack traces on application crash.

However, this usually isn’t the case, so it is required to enable ‘programmer options’ on the Android device, and then enable USB debugging on the device in order to access that information.

It also requires `adb` application to be installed on an external computer. If all these prerequisites are satisfied, the crash logs can be fetched using the following command:

adb logcat --buffer=crash

If you happen to know how to access the crash information from the Android device itself and wouldn’t mind sharing that information with me, I’d be grateful.

Running the desktop client on Android

While it might seem ridiculous from the usability perspective, it may sometimes be convenient to be able to test the desktop client from Android.

The exact tutorial on running the X11 server in Termux can be found at https://wiki.termux.com/wiki/Graphical_Environment but once all the packages and apps are installed and configured, the VNC server can be run by typing (in Termux)

vncserver -localhost

Once this is done, it is also required to type

export DISPLAY=":1"

to be able to run the desktop client from a particular bash session.

Older prototypes

The older prototypes of GRASP (for Android only) can be found in the https://github.com/panicz/grasp-android repository (which is now archived).

There is an even older prototype which runs in Racket, and which can be found in the https://github.com/panicz/sracket repository (the 5.rkt file).