Extending the Library

Fast Forward Iterators does not require a container, a framework integration, or package-specific service registration. Extension is intentionally simple: build on top of the public iterator base classes and pass around ordinary PHP iterables.

Recommended extension workflow

  1. accept iterable as input whenever possible;
  2. normalize it with IterableIterator if you need a consistent Iterator ;
  3. choose the smallest countable base class that matches your design;
  4. keep the output shape obvious in both naming and documentation.

Choosing the right base class

Base class Best for Example ideas
CountableIteratorAggregate generator-based or delegated iteration chunking, mapping, flattening, lazy adapters
CountableIteratorIterator wrappers around an existing iterator transforming values, remapping keys, peeking helpers
CountableFilterIterator boolean acceptance rules path filters, record filters, validation gates
CountableIterator full stateful control custom navigation, multi-source coordination, specialized range logic

Practical advice

  • Prefer aggregates when you can express the behavior with yield .
  • Prefer wrappers when you want to preserve most behavior of an inner iterator.
  • Document whether your iterator preserves original keys or emits normalized sequential keys.
  • Call out whether a class buffers values in memory. This matters for LookaheadIterator , grouping iterators, and generator replay strategies.

No hidden framework hooks

This package does not expose:

  • aliases;
  • singletons;
  • framework-specific service providers;
  • PSR-11 container bindings.

That keeps custom integration straightforward: instantiate the iterator directly where you need it, or register it in your own application container using normal PHP construction rules.