eu.bandm.sig.adlib2

Class SignalPort<A>

java.lang.Object

eu.bandm.sig.adlib2.SignalPort<A>

Type Parameters:

A - the type of values produced by this signal source

All Implemented Interfaces:

AbstractSignalSource, CompilableDataFlow, SignalSource<A>, Supplier<A>

public class SignalPort<A>
extends Object
implements SignalSource<A>

A receptacle for a signal source than can be plugged at runtime, even if compiled.

An instance of this class, when used directly, acts as a dynamic proxy that delegates all method invocations to a pluggable input signal source. The currently plugged input is looked up via getInput() at every delegation event, such that re-plugging via setInput(SignalSource) has immediate effect.

If an instance of this class is compiled, usually as a subcomponent of a complex signal network, then the compiled code shares the pluggable state of the original orig, and will dynamically delegate to the input signal source returned by orig.getInput(). Thus even complex network modules with multiple inputs and outputs can be compiled to monolithic code, but configured dynamically, by

1. creating an interpreted version of the module with inputs realized as ports, i.e. instances of SignalSource and its companion classes,
2. compiling the module,
3. retaining references to the ports,
4. plugging the actual inputs into the ports,
5. using the output signal sources of the compiled version in place of the interpreted one.

The pluggable input signal source can be set to null, which will cause the get() method of this object to fail at runtime with NullPointerException.

Constructor Summary

Constructors

Constructor and Description
SignalPort(Class<? super A> valueClass, SignalSource<A> input) Creates a new instance with the specified initial input.
SignalPort(Class<A> valueClass) Creates a new instance with no specified initial input.

Method Summary

Modifier and Type	Method and Description
Consumer<CompilationContext>	compileDataFlow() Returns a code generator for outputting the value of this entity.
A	get() Returns the current value of this signal source.
SignalSource<? super A>	getInput() Returns the current input signal source.
Class<? super A>	getValueClass() Returns the type of values produced by this entity.
void	setInput(SignalSource<A> input) Sets the current input signal source.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface eu.bandm.sig.adlib2.SignalSource

choose, choose, choose, choose, clock, compileMainSignalSource, constant, constant, delayed, delayed, delayedFeedback, delayedFeedback, eq, getConstant, guard, hasConstant, invariant, map, map, neq, power, probe, publishStoredValueVariable, relateWith, sampleAndHold, stored, zipWith

Methods inherited from interface eu.bandm.sig.adlib2.compile.CompilableDataFlow

compileDataFlowTo, hasDataFlowIO

Constructor Detail

SignalPort

public SignalPort(Class<A> valueClass)

Creates a new instance with no specified initial input.

Parameters:

valueClass - the type of values produced by this signal source

SignalPort

public SignalPort(Class<? super A> valueClass,
                  SignalSource<A> input)

Creates a new instance with the specified initial input.

Parameters:

valueClass - the type of values produced by this signal source

input - the input signal source

Throws:

ClassCastException - if the type of values produced by the given (non-null) input signal source is not a subtype of the type specified for this signal source.

Method Detail

getInput

public SignalSource<? super A> getInput()

Returns the current input signal source.

setInput

public void setInput(SignalSource<A> input)

Sets the current input signal source.

Throws:

ClassCastException - if the type of values produced by the given (non-null) input signal source is not a subtype of the type specified for this signal source.

See Also:

getValueClass()

get

public A get()

Returns the current value of this signal source.

The value may be either computed on demand, or retrieved from storage.

Implementations of this method should have no side effect.

This implementation always delegates to getInput().get().

Specified by:

get in interface SignalSource<A>

Specified by:

get in interface Supplier<A>

Returns:

the current value of this signal source

getValueClass

public Class<? super A> getValueClass()

Returns the type of values produced by this entity.

For signals of primitive value type, the result will be the corresponding pseudoclass.

This implementation returns Object.class. Subclasses may override this method to provide more specific type information.

Specified by:

getValueClass in interface CompilableDataFlow

Specified by:

getValueClass in interface SignalSource<A>

Returns:

the type of signal values that this entity produces

See Also:

Class.isPrimitive()

compileDataFlow

public Consumer<CompilationContext> compileDataFlow()

Description copied from interface: SignalSource

Returns a code generator for outputting the value of this entity.

This implementation generates code to invoke this.get().

Specified by:

compileDataFlow in interface CompilableDataFlow

Specified by:

compileDataFlow in interface SignalSource<A>