call method

Future<T> call(T input)

Executes the pipeline with the given input.

This method:

1. Builds the middleware chain in reverse order (right-to-left)
2. Each middleware wraps the previous handler
3. Calls the complete chain with the input

The chain is built as: mw1(mw2(mw3(...(core_handler)))) where middleware are ordered as they were added via use.

Returns a Future that resolves when the entire pipeline completes. If any middleware throws an exception, it propagates through the Future.

Parameters:

• input: The value to process through the pipeline

Returns: A Future containing the processed value

Example:

final pipeline = Pipeline<int>();
pipeline.use((next) => (value) async => await next(value * 2));
final result = await pipeline(5); // Returns 10

Implementation

Future<T> call(T input) {
  var handler = _handler<T>;

  // Build chain right to left: first middleware ends up outermost
  for (final mw in _middlewares.reversed) {
    final next = handler;
    handler = mw(next);
  }
  return handler(input);
}