# TextPartNode

Represents a dynamic text part (e.g. `${text}`).

## Signatures

```ts
export declare class TextPartNode {
    readonly _tag: "text-part";
    readonly index: number;
    constructor(index: number);
}
```

## Why

A retained native text target supports O(1) scalar updates with respect to
the surrounding DOM tree.

## Ownership and lifetime

The AST owns only an index; the mounted render Scope owns the text updater.

## Constructor

Creates dynamic text syntax.

## Property: _tag

Dynamic-text discriminant.

## Property: _tag: Why

Selects a retained native Text target for O(1) scalar updates.

## Property: _tag: Ownership and lifetime

Immutable AST metadata.

## Property: index

Interpolation index driving the retained text target.

## Property: index: Why

Locates the producer without walking the surrounding tree.

## Property: index: Ownership and lifetime

Immutable scalar metadata; the render Scope owns the producer.

## Examples

```ts
import { TextPartNode } from "@typed/template/Template"

const part = new TextPartNode(0)
```