eu.bandm.sig.adlib2

Class AbstractSignalSourceChooser

java.lang.Object

eu.bandm.sig.adlib2.AbstractSignalSourceChooser

Direct Known Subclasses:

BooleanSignalSourceChooser, DoubleSignalSourceChooser, FloatSignalSourceChooser, IntSignalSourceChooser, LongSignalSourceChooser, SignalSourceChooser

public abstract class AbstractSignalSourceChooser
extends Object

Base class for signal sources of that choose dynamically from a fixed collection of inputs.

Subclasses may realize time-dependent choice by providing a selector signal source, and associate an input signal source with each of the valid selector values.

Efficient compilation is ensured by collecting the code branches to choose from in an int-indexed table that can be used with a switch statement.

Since signals have no means to communicate errors, the choice should be total, that is defined at all times. Since this is technically difficult to ensure statically, signal sources derived from this base class are permitted to fail when no input can be chosen. It is recommended that IndexOutOfBoundsException be thrown if an invalid selector value has occurred, but that the default value of the signal type is produced if no input signal source has been associated with the current, valid selector value.

Constructor Summary

Constructors

Constructor and Description
AbstractSignalSourceChooser()

Method Summary

Modifier and Type	Method and Description
static <E extends Throwable> void	alwaysThrow(E throwable)
protected abstract Consumer<CompilationContext>	compileConvertToInt() Returns a code generator for converting a value that represents the current selection to an index of type int.
Consumer<CompilationContext>	compileDataFlow()
protected abstract Consumer<CompilationContext>	compileDefaultValue() Returns a code generator for loading the default value of the signal type on the operand stack.
protected Consumer<CompilationContext>	compileOrDefault(VariableContext.Variable result, CompilableDataFlow branch)
protected abstract Map<Integer,Consumer<CompilationContext>>	getCases(VariableContext.Variable result) Returns a map with int-indexed code generators for branches to choose from.
protected abstract CompilableDataFlow	getSelector() Returns an entity that can be compiled to code that outputs a value that represents the current selection.

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractSignalSourceChooser

public AbstractSignalSourceChooser()

Method Detail

getSelector

protected abstract CompilableDataFlow getSelector()

Returns an entity that can be compiled to code that outputs a value that represents the current selection. The value can be of any type.

See Also:

CompilableDataFlow.getValueClass()

compileConvertToInt

protected abstract Consumer<CompilationContext> compileConvertToInt()

Returns a code generator for converting a value that represents the current selection to an index of type int.

compileDefaultValue

protected abstract Consumer<CompilationContext> compileDefaultValue()

Returns a code generator for loading the default value of the signal type on the operand stack.

compileDataFlow

public Consumer<CompilationContext> compileDataFlow()

getCases

protected abstract Map<Integer,Consumer<CompilationContext>> getCases(VariableContext.Variable result)

Returns a map with int-indexed code generators for branches to choose from. The returned map should contain an entry for every valid index. The method compileOrDefault(eu.bandm.tools.lljava.live.VariableContext.Variable, eu.bandm.sig.adlib2.compile.CompilableDataFlow) may be used to populate the map.

Parameters:

result - the variable that all branches should output to

See Also:

compileConvertToInt()

compileOrDefault

protected Consumer<CompilationContext> compileOrDefault(VariableContext.Variable result,
                                                        CompilableDataFlow branch)

alwaysThrow

public static <E extends Throwable> void alwaysThrow(E throwable)
                                              throws E extends Throwable

Throws:

E extends Throwable