Notes on the design of Metel | Metel Language Wiki

language design

A Struct Is Already a Row

October 18, 2026by Vladislav Parfeniuc15 min read

The first post said records would get their own writeup once the design was further along. It is — and the design changed on the way. So this is both the promised post and a correction to it.

language design

Introducing Metel

July 15, 2026by Vladislav Parfeniuc8 min read

Metel is an experimental language built around four commitments, roughly in order: compile-time safety, explicitness, expressivity, and — eventually — performance. It brings together ideas from across modern language design — ownership, capabilities, effects, structural types, and explicit allocation — to ask how they can be combined into a single coherent system.

Here is a small taste of the language:

fun main() {
    let name := "Metel";
    let answer: Perhaps<i64> := Some { value = 42 };
    println("${name} says the answer is ${answer.yolo()}");
}

.yolo() is not a typo — more on that name below.