Package net.vleo.timel.function

Interface Function<T>

Type Parameters:

T - Return value Java type

public interface Function<T>

An interface to define a TimEL function. This interface should be annotated with FunctionPrototype (or FunctionPrototypes) so to properly declare the function prototype.

Author:

Andrea Leofreddi

Method Summary

Modifier and Type	Method	Description
UpscalableIterator<T>	evaluate(Interval interval, ExecutorContext context, net.vleo.timel.impl.upscaler.Upscaler<T> upscaler, net.vleo.timel.impl.downscaler.Downscaler<T> downscaler, net.vleo.timel.impl.target.Evaluable<?>... arguments)	Evaluates the function.
static <T> UpscalableIterator<T>[]	evaluateAll(Interval interval, ExecutorContext context, net.vleo.timel.impl.target.Evaluable<? extends T>... arguments)	Convenience function to evaluate all the given arguments for the same interval and context.
default Optional<Type>	resolveReturnType(Type proposed, Map<String,Type> variables, Type... argumentTypes)	Helps the compiler to resolve the return type for a possible function call candidate.
default Optional<Type<?>>	specializeVariableTemplate(String variable, TemplateType template, Type<?>... argumentTypes)	Binds a variable to a template specialization when dealing with template types.

Method Detail

specializeVariableTemplate

default Optional<Type<?>> specializeVariableTemplate(String variable,
                                                     TemplateType template,
                                                     Type<?>... argumentTypes)

Binds a variable to a template specialization when dealing with template types.

The default implementation allows variables to bind only to a particular template specialization, if matched by all occurrences.

By overriding this method, one can change the default behavior so to accept different templates specializations.

Parameters:

variable - Variable name to specialize

template - Template type to specialize

argumentTypes - List of argument types

Returns:

The deduced template type if any

resolveReturnType

default Optional<Type> resolveReturnType(Type proposed,
                                         Map<String,Type> variables,
                                         Type... argumentTypes)

Helps the compiler to resolve the return type for a possible function call candidate. This method is invoked by the compiler due to one of the following conditions:

• The function's metadata has no information about the return type
• The function return type is a template
• The function return type is bound to a variable, that resolved to a template

The default implementation is to return empty, which will make the function a non match.

Parameters:

proposed - The return value guessed so far

variables - A map of the variable types resolved

argumentTypes - All argument types

Returns:

The specialized return type if any

evaluate

UpscalableIterator<T> evaluate(Interval interval,
                               ExecutorContext context,
                               net.vleo.timel.impl.upscaler.Upscaler<T> upscaler,
                               net.vleo.timel.impl.downscaler.Downscaler<T> downscaler,
                               net.vleo.timel.impl.target.Evaluable<?>... arguments)

Evaluates the function.

Parameters:

interval - Evaluation interval

context - Executor context

upscaler - Result upscaler. This one is provided to be coherent with the expected return type.

downscaler - Result downscaler. This one is provided to be coherent with the expected return type.

arguments - List of arguments to evaluate.

Returns:

Evaluation result iterator

evaluateAll

static <T> UpscalableIterator<T>[] evaluateAll(Interval interval,
                                               ExecutorContext context,
                                               net.vleo.timel.impl.target.Evaluable<? extends T>... arguments)

Convenience function to evaluate all the given arguments for the same interval and context.

Type Parameters:

T - Expected return value Java type

Parameters:

interval - Evaluation interval

context - Evaluation context

arguments - Arguments to evaluate

Returns:

An array containing the evaluation result