Morphity

A functional, trait-based polymorphism system for JavaScript/TypeScript using proxies and symbols.

Quick Start

import { createContainer, addSlot, defineTrait } from 'jsr:@justbyitself/morphity'

// Create a container
const container = createContainer()

// Define slots
const toIterable = addSlot(container)
const map = addSlot(container)

// Define traits declaratively
defineTrait({
  requires: value => Array.isArray(value),
  provides: [[toIterable, proxy => proxy]]
})(container)

defineTrait({
  requires: [toIterable],
  provides: [[map, proxy => fn => {
    const result = []
    for (const item of toIterable(proxy)) result.push(fn(item))
    return result
  }]]
})(container)

// Use it - traits auto-apply!
map([1, 2, 3])(x => x * 2)  // [2, 4, 6]

Features

• Slot-based polymorphism - Define behaviors through slots
• Auto-applying traits - Traits apply automatically based on predicates and dependencies
• Composable traits - Build complex behaviors from simple traits
• Data-last support - Easy to wrap slots for functional pipelines
• Dependency resolution - Automatic path finding and cycle detection
• Zero dependencies - Pure JavaScript with no external dependencies

Documentation

See GUIDE.md for detailed documentation and examples.