---
title: A new release of Mist in may 2026 (0.0.3-alpha4), what's new
author: Klesti Selimaj
date: 2026-05-19
---

## Performance
On my machines, the `mist-test` usually gets transpiled at ~13ms, which is good, but i'm unsatisfied, so i made it "transpile" at ~500µs, sometimes even 275µs, this of course is very dependent of the schedule and overhead.

This was achieved by caching the file's timestamps, and this also saves the Rust compiler a lot of work since it has the same caching system.

## Errors & Mapping
You will notice that the output of the mist code contains something like this:
```rust
/* 9:5 */
let args: Vec<String> = env::args().collect();
/* 11:5 */
if args.len() < 2
{
    /* 12:9 */
    print_usage();
    /* 13:9 */
    process::exit(1);
}
```

Those are mappings, the line of the rust file will translate to the line on the comment, example:
```bash
src/main.mist:12:9
 Error: cannot find function `print_usage` in this scope
        process::exit(1);
```

This is what the input is:
```mist
Vec<String> args = env::args().collect();

if (args.len() < 2) {
    print_usage();
    process::exit(1);
}
```

The error itself is taken via `--message-format=json` on `cargo` with the `cargo_metadata` crate.


## Syntax changes

### Match
Match patterns now allow `|`:

```mist
match (args[1].as_str()) {
    "run" | "build" | "check" | "r" | "b" | "c" => {
        var (config, root) = transpiler::build();
    }

    _ => {}
}
```

## Strings & Macros
After using macros and strings, i noticed that there was bugs everywhere, i now ensure more stable macros, and strings now allow different escape sequences.


## Variables and other statements
Fixed variables declarations like 
```mist
Vec<String> args;
```
And also function calls:
```mist
my_func();
```

The reason why bugs occur with these statements is due to ambiguity, at first, they are right, for example:
```mist
// <type> <pattern>
my_func (); // () used to be a pattern.
```

This fix is not perfect, you may encounter the same issues when passing arguments that are also within the pattern range (meaning not full expressions).