Snap! version 8 introduces more than 700 documented fixes and enhancements book-ended by two major new features: smart script pics and metaprogramming. “Smart script pics” enable users to easily share images that embed the program inside the image file! All you need to do is simply drag-and-drop and images to share code. This simple feature makes projects far more collaborative by reducing the burden to share code.

The second, and arguably more powerful feature, is bringing metaprogramming to a blocks-based programming language! The idea of metaprogramming is a powerful one; it allows programmers to write programs that generate other programs, and has many implications for teaching computer science. It allows instructors and students to easily build autograders, libraries, abstract data types, and more.

Snap! accomplished this by adding just a few blocks that provided the ability to define new blocks, as well as query and modify existing scripts, bringing the power of reflection to a visual programming language. In this demo we’ll explore hands-on ways to use smart script pics and metaprogramming to enhance teaching CS. Overall, the new Snap! 8 release represents more than 12 months of hard work by a dedicated team, and we would be delighted to share these new features with our SIGCSE family.

All projects and examples from this demonstration will be shared at https://bjc.link/snap-sigcse23