leannode-core/README.md

Simple Node.js wrapper for Lean 4 theorem prover

# leannode-core

A minimal Node.js wrapper for the Lean 4 theorem prover.

## Installation

```bash
npm install leannode-core
```

**Prerequisites:** You must have [Lean 4](https://leanprover.github.io/) installed and available in your PATH.

## Usage

```javascript
const LeanRunner = require('leannode-core');

// Basic evaluation
const result = await LeanRunner.run('#eval 2 + 3');
console.log(result.stdout); // "5"

// Define and evaluate
const code = `
def factorial : Nat → Nat
| 0 => 1  
| n + 1 => (n + 1) * factorial n

#eval factorial 5
`;

const result = await LeanRunner.run(code);
console.log(result.stdout); // "120"
```

## API

### `LeanRunner.run(leanCode, options?)`

Executes Lean code and returns a promise with the result.

**Parameters:**
- `leanCode` (string): The Lean code to execute
- `options` (object, optional):
  - `args` (array): Additional command line arguments for Lean
  - `cwd` (string): Working directory for the Lean process
  - `env` (object): Environment variables

**Returns:**
Promise resolving to:
```javascript
{
  stdout: string,  // Standard output from Lean
  stderr: string,  // Standard error from Lean  
  exitCode: number // Process exit code (0 = success)
}
```

## Testing

```bash
npm test
```

## License

MIT