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createIterable()

createIterable<T>(factory): Iterable<T>

Creates a lazy, re-iterable sequence from a factory that produces a "next" function.

The factory is called each time [Symbol.iterator]() is invoked, ensuring the iterable can be traversed multiple times. Each "next" call returns Some(value) for the next element or None to signal completion.

This is the core of the GoF Iterator pattern: it decouples traversal logic (the next function) from the data source.

Type Parameters​

T: T​

The element type

Parameters​

factory: () => () => Option<T>​

A function that creates a stateful "next" supplier

Returns: Iterable<T>​

A lazy Iterable

Since​

2.4.0

Example​

// Iterate over a tree in depth-first order
const treeIter = createIterable(() => {
  const stack = [rootNode];
  return () => {
    if (stack.length === 0) return none;
    const node = stack.pop();
    if (!node) return none;
    stack.push(...node.children);
    return some(node.value);
  };
});

for (const value of treeIter) { ... }