# Graph with Reflection and Rewrite Nodes

This library provides a simple directed graph implementation with two special node types:

- **ReflectionNode** – forwards all input values to its outputs unchanged.
- **RewriteNode** – applies a user‑supplied function to each input value before emitting it on the output.

## Installation

```bash
npm install graph-reflection-rewrite
```

## Usage

```ts
import { Graph, RewriteFunction } from 'graph-reflection-rewrite';

const graph = new Graph();

// Create a reflection node
const refNode = graph.createNode('reflection');

// Create a rewrite node that doubles numbers
const rewriteNode = graph.createNode('rewrite', {
  func: (value: number) => value * 2
});

// Connect nodes
graph.addEdge(refNode.id, 'output', rewriteNode.id, 'input');

// Provide initial input to the reflection node
refNode.inputs.set('input', 5);

// Run the graph
graph.run();

// Inspect results
console.log(rewriteNode.outputs.get('input')); // 10
```

## API

### `Graph`

| Method | Description |
|--------|-------------|
| `createNode(type, options?)` | Creates a node of the specified type. For `rewrite` nodes, `options` must contain a `func` property. |
| `addNode(node)` | Adds an existing node instance to the graph. |
| `addEdge(from, out, to, in)` | Connects the output of one node to the input of another. |
| `run()` | Executes all nodes in the graph, propagating data along edges. |
| `getNode(id)` | Retrieves a node by its ID. |

### `BaseNode`

| Property | Type | Description |
|----------|------|-------------|
| `id` | `string` | Unique identifier. |
| `type` | `string` | Node type (`reflection` or `rewrite`). |
| `inputs` | `Map<string, any>` | Input values keyed by input names. |
| `outputs` | `Map<string, any>` | Output values keyed by output names. |
| `process()` | `void` | Override to implement node logic. |

### `ReflectionNode`

- Inherits from `BaseNode`.
- `process()` copies all inputs to outputs with the same keys.

### `RewriteNode`

- Inherits from `BaseNode`.
- Constructor accepts a `func: (value: any) => any`.
- `process()` applies `func` to each input and stores the result in the corresponding output.

## Testing

Run the test suite with:

```bash
npm test
```

The project uses Jest with TypeScript support (`ts-jest`).

## License

MIT