# Iterable<E>.generate constructor

Iterable<E>.generate(int count, [ E generator(int index) ])

Creates an `Iterable` which generates its elements dynamically.

The generated iterable has `count` elements, and the element at index `n` is computed by calling `generator(n)`. Values are not cached, so each iteration computes the values again.

If `generator` is omitted, it defaults to an identity function on integers `(int x) => x`, so it may only be omitted if the type parameter allows integer values. That is, if `E` is one of `int`, `num`, `Object` or `dynamic`.

As an `Iterable`, `new Iterable.generate(n, generator))` is equivalent to `const [0, ..., n - 1].map(generator)`.

## Implementation

    factory Iterable.generate(int count, [E generator(int index)]) {
      if (count <= 0) return new EmptyIterable<E>();
      return new _GeneratorIterable<E>(count, generator);
    }