# MatchAst.Layout

A function that wraps matched content using reactive params.

## Signatures

```ts
interface Layout {
    type: "layout";
    matches: ReadonlyArray<MatchAst>;
    layout: LayoutType<any, any, any, any, any, any, any>;
}
```

## Why

Layout output, errors, and services compose in the surrounding Matcher type.

## Ownership and lifetime

`Layout` describes plain readonly AST data. Routes and Matchers retain the concrete nodes they receive by reference; the type itself owns no resource.

## Property: layout

Constructs a Match AST boundary around a parameter-aware layout.

## Property: layout: Why

Layout ownership and nesting remain explicit in the compiled matcher tree.

## Property: layout: Ownership and lifetime

The layout function is retained by identity so the executor can reuse its child Scope across
parameter-only transitions.

## Property: matches

The ordered child matcher nodes wrapped by this boundary.

## Property: matches: Why

Order is preserved for candidate and guard fallthrough.

## Property: matches: Ownership and lifetime

The layout boundary retains this ordered child array by reference; it owns no child execution
Scope until the Matcher runs.

## Property: type

The discriminant identifying this AST variant.

## Property: type: Why

Exhaustive switches can interpret syntax without instanceof checks or hidden classes.