call abstract method

FutureOr<Object?> call(
  1. String function,
  2. Object? input,
  3. BallCallable engine
)

Executes function with the given input value.

engine is a BallCallable that lets this handler compose other ball functions (user-defined or from other handlers) without holding a direct engine reference:

final sub = engine('std', 'subtract',
    {'left': highPrice, 'right': lowPrice});

Throws BallRuntimeError when function is not supported.

Implementation

FutureOr<Object?> call(String function, Object? input, BallCallable engine);