Vision

The author of ALT has a long burning desire to build a better spreadsheet for citizen developers. Just imagine a spreadsheet, but now with all the nice features that we care about as software developers!

• Typed
• Versioned
• Modular
• Abstracted
• Secure
• Distributed
• Interactive
• Visual*
• Etc

ALT has almost all of the features available to make that dream become a reality.

However, the current implementation is not nearly efficient enough to be used by end users. Luckily, there are many performance improvements that can be considered:

• Exploit sorting/ordering to reduce indexing from O(n) to O(log(n))
• Add specialized rewrite rules for common idioms
• Compile ALT programs
• Dynamically add indexes to frequently used data
• Dynamically decide on the best (internal) data structure for a value
• Incrementally re-compute only what is necessary

ALT is currently closed source because managing an open source project requires a lot of effort which is not the focus of the author. But, depending on the feedback and reception, ALT will probably be open sourced in the near future. If you are feeling adventurous and can’t wait for ALT to be open sourced, you can hack the javascript code in the browser!

It would be very nice to have a formal specification of ALT’s (term rewriting) semantics in Coq or Isabelle/HOL. With such specification we could (hopefully!) prove that ALT has the global confluence property and that ALT terminates for all terms/programs (and most importantly, that programs with cycles always terminate). We could also use the formal specification to check whether certain rewrite rules are admissable, or prove little theorems.