# Package cascading.operation

Interface Summary
Interface | Description
--- | ---
Aggregator<Context> | An Aggregator takes the set of all values associated with a unique grouping and returns zero or more values.
AggregatorCall<C> | Interface AggregatorCall provides access to the current `Aggregator` invocation arguments.
Assertion<PC> | Interface Assertion is the base interface for all stream assertions.
Buffer<Context> | A Buffer is similar to an `Aggregator` by the fact that it operates on unique groups of values.
BufferCall<C> | Interface BufferCall provides access to the current `Buffer` invocation arguments.
Filter<Context> | Interface Filter marks a given `Operation` as a filter, as opposed to being a `Function`.
FilterCall<C> | Interface FilterCall provides access to the current `Filter` invocation arguments.
Function<Context> | Interface Function marks a given `Operation` as a function, as opposed to being a `Filter`.
FunctionCall<C> | Interface FunctionCall provides access to the current `Function` invocation arguments.
GroupAssertion<C> | Class GroupAssertion is a kind of `Assertion` used with the `Every` pipe Operator.
GroupAssertionCall<C> | Interface GroupAssertionCall provides access to the current `GroupAssertion` invocation arguments.
Operation<Context> | Interface Operation is the base interface for all functions applied to `Tuple` streams.
OperationCall<Context> |
PlannedOperation<Context> | Interface PlannedOperation is implemented by all `Operation` implementations that use a `PlannerLevel` value to inform the `FlowPlanner` how to treat the operation during job planning.
PlannerLevel | Interface PlannerLevel is the base interface for `DebugLevel` and `AssertionLevel` enum types.
ValueAssertion<C> | Class ValueAssertion is a kind of `Assertion` used with the `Each` pipe Operator.
ValueAssertionCall<C> | Interface ValueAssertionCall provides access to the current `ValueAssertion` invocation arguments.

Class Summary
Class | Description
--- | ---
BaseOperation<Context> | Class BaseOperation is the base class of predicate types that are applied to `Tuple` streams via the `Each` or `Every` `Pipe`.
ConcreteCall<C> | Class OperationCall is the common base class for `FunctionCall`, `FilterCall`, `AggregatorCall`, `ValueAssertionCall`, and `GroupAssertionCall`.
Debug | Class Debug is a `Filter` that will never remove an item from a stream, but will print the Tuple to either stdout or stderr.
Identity | The Identity function simply passes incoming arguments back out again.
Insert | Class Insert adds literal values to the Tuple stream.
NoOp | Class NoOp does nothing.

Enum Summary
Enum | Description
--- | ---
AssertionLevel | Enum AssertionLevel designates the level of a given `Assertion` instance.
Debug.Output |
DebugLevel | Enum DebugLevel designates the level of a given `Debug` instance.

Exception Summary
Exception | Description
--- | ---
AssertionException | Class AssertionException is the exception that must be thrown when an `Assertion` fails.
OperationException | Class OperationException is thrown by `BaseOperation` classes.