*Update on the Mu computer's memory-safe language*

Progress has been slow over the holiday season because I've been working on a paper about Mu for https://2020.programming-conference.org/home/salon-2020

But functions can now return outputs.

```
fn foo a: int -> result/eax: int {
result <- copy a
increment result
}
```

Project page: https://github.com/akkartik/mu#readme

Sources for the memory-safe language, now at 5kLoC: http://akkartik.github.io/mu/html/apps/mu.subx.html

Caveats: no checking yet, only int types supported.

*Update on the Mu computer's memory-safe language*

Still no type-checking or memory-safety, but we can now write any programs with int variables.

There's still no 'var' keyword, so we can't define local variables yet. But that's not insurmountable; just pass in extra arguments for any space you want on the stack 😀

```
result <- factorial n 0 0 0
```

*Update on the Mu computer's memory-safe language*

Basic language is done! Here's factorial. (Compare https://mastodon.social/@akkartik/102749590808384215.)

Still todo:
- user-defined types
- type checking and memory-safety

In other words, I'm about a third of the way there 😂 More detailed todo list: https://lobste.rs/s/pv8jpr/what_are_you_doing_this_week#c_5ymbsa

(More details on the Mu project: http://akkartik.name/post/mu-2019-1. Repo: https://github.com/akkartik/mu)

A brief timeline of the Mu computing stack

Jul 6, 2014: commit 0, tree-based interpreter for a statement-oriented language (https://github.com/akkartik/mu)

Jul 19, 2017: commit 3930, start of SubX machine code (http://akkartik.name/post/mu-2019-1)

Sep 20, 2018: started building SubX in SubX (https://mastodon.social/@akkartik/100779355103829305)

Jul 24, 2019: SubX in SubX done, commit 5461 (https://mastodon.social/@akkartik/102495274992610155)

Oct 2, 2019: started designing the Mu memory-safe language (http://akkartik.name/post/mu-2019-2)

Oct 29: started http://akkartik.github.io/mu/html/apps/mu.subx.html

I'll be in Porto, Portugal on Mar 24 to present a paper on Mu at the Convivial Computing Salon: https://2020.programming-conference.org/home/salon-2020#event-overview

Hoping for some great conversation and disagreements.

*Update on the Mu computer's memory-safe language*

Mu just got its first couple of non-integer types: addresses and arrays. As a result, the factorial app can _finally_ run its tests based on command-line args.

http://akkartik.github.io/mu/html/apps/factorial.mu.html

Addresses are accessed using a '*' operator. Arrays are accessed using an 'index' instruction that takes an address (addr array T) and returns an address (addr T).

Literal indexes aren't supported yet.

Open q: indexing arrays of non-power-of-2 element sizes.

*Update on the Mu computer's memory-safe language*

Still no type-checking or memory-safety, but we have partial support for arrays and product types. Still several sharp edges:

- can't index an array with a literal
- can't index an array with non-power-of-2-sized elements
- can allocate but not use arrays/records on the stack

My todo list is growing. But work per item is shrinking. Hopefully there's an asymptote.

(More details: http://akkartik.name/post/mu-2019-1. Repo: https://github.com/akkartik/mu)

Lots of words in this commit message about liveness analysis, and it probably still makes no sense to anybody.

https://github.com/akkartik/mu/commit/4032286f9bb231139b733e5444b862006d3b9119

Hopefully it'll make sense to me at least in a month or two.