Dex has a reactive notebook and literate programming environment in dex web.

dex web is great for interactive development, thanks to features like:

• Direct rendering of Dex source code, no additional non-standard data formats like .ipynb.
• Live reloading triggered by source code updates.
• Syntax highlighting.

However, the Dex compiler has a lot more information about source code that's not being visualized currently:

• Expression and declaration types
• Expression parse trees
• Definition-use chains (occurrences of the same binder)

This issue tracks adding IDE information to the web environment via tooltips, visible when hovering the cursor over code.

Tooltips will make it easy to access information computed by the Dex compiler, and will make reading and writing Dex code more interactive – and hopefully more fun too.

Related resources

• Related issue: Implement the Language Server Protocol (LSP) for Dex #414
• Tooltips / web environments for other programming languages
  • Haskell's Haddock rendering, with hyperlinks and tooltips on hover: example
  • Koka's web rendering, with hyperlinks and tooltips on hover: example
  • Many more
• Early tooltip mockup in Jamboard