# Evaltor: Typst plugin for unit-aware calculations

I initially wanted to use [numbat](https://github.com/sharkdp/numbat) but since it requires access to filesystem (which is not allowed in typst), I ended up choosing [fend](https://printfn.github.io/fend) as the backend.

If I find `fend` to be limiting, I will try to implement in-memory module importer in `numbat` where all the `nbt` files are imported at compile-time.

Built using [typst-wasm](https://github.com/sjfhsjfh/typst-wasm).

First compile the rust code to wasm32 using:

```sh
rustup target add wasm32-unknown-unknown
cargo build --release --target wasm32-unknown-unknown
```

Then install the typst package locally using [tlp](https://tangled.org/vidyasagarv.com/tlp) or [utpm](https://github.com/typst-community/utpm):

```sh
tlp init
```

Then you can directly use in typst like:

```typ
#import "@local/evaltor:0.1.0": print_eval

#print_eval("2 km + 30 m")
```

will produce the output:

```
2 km + 30 m = 2.03 km  
```

For more details, see [examples.typ](tests/examples.typ) and [fend manual](https://printfn.github.io/fend/documentation/).


## Plans
- Add [rink](https://github.com/tiffany352/rink-rs/) as a backend, gives preference to unit over operation unlike fend.
- Use [unify](https://github.com/ChHecker/unify) or [zero](https://github.com/Mc-Zen/zero) to format input and output.
- Check out [numr](https://github.com/nasedkinpv/numr)