Molniya

Appearance

Introduction

Installation ​

Molniya is distributed as an npm package and requires the Bun runtime.

Prerequisites ​

  • Bun 1.0 or later
  • TypeScript 5.0 or later (for type checking)

Install with Bun ​

bash
bun add molniya

TypeScript Configuration ​

Molniya is written in TypeScript and provides full type definitions. Ensure your tsconfig.json includes:

json
{
  "compilerOptions": {
    "module": "ESNext",
    "moduleResolution": "bundler",
    "target": "ES2022",
    "strict": true,
    "esModuleInterop": true
  }
}

Verify Installation ​

Create a test file to verify everything works:

typescript
// test.ts
import { DataFrame, DType, createSchema, unwrap } from "molniya";

const schema = unwrap(createSchema({
  id: DType.int32,
  name: DType.string
}));

const df = DataFrame.empty(schema, null);
console.log("Column names:", df.columnNames);

Run it:

bash
bun test.ts

Development Setup ​

If you're contributing to Molniya or want to run the test suite:

bash
# Clone the repository
git clone https://github.com/your-org/Molniya.git
cd Molniya

# Install dependencies
bun install

# Run tests
bun test

# Run linter
bun run lint

# Format code
bun run format

Troubleshooting ​

"Cannot find module 'Molniya'" ​

Make sure you're using Bun to run your code, not Node.js:

bash
# Correct
bun run myfile.ts

# Incorrect - won't work
node myfile.ts
npx ts-node myfile.ts

Type errors with schema definitions ​

Ensure your TypeScript configuration uses "strict": true for the best type inference experience.

Memory issues with large files ​

Molniya streams CSV files by default, but some operations (like sorting) require loading data into memory. If you encounter memory issues:

  1. Use .limit() before operations that materialize data
  2. Process files in chunks manually if needed
  3. Consider using .filter() early in your pipeline to reduce data volume