com.github.ykrasik.jaci.util.function

Class MoreSuppliers

java.lang.Object

com.github.ykrasik.jaci.util.function.MoreSuppliers

public final class MoreSuppliers
extends java.lang.Object

Supplier related utilities.

Method Summary

Modifier and Type	Method and Description
static <T> Spplr<T>	cache(Spplr<T> supplier) Wrap the given supplier in a supplier that will only call the underlying supplier once, and then cache the returned value.
static <T,R> Spplr<R>	map(Spplr<T> supplier, Func<T,R> function) Create a supplier that will transform the value returned by the given supplier by invoking the given function on it.
static <T> Spplr<T>	of(T value) Create a supplier that will return the given value.
static <T> Spplr<java.util.List<T>>	reflectionListSupplier(java.lang.Object instance, java.lang.String methodName, java.lang.Class<T[]> suppliedClass) Create a supplier that will invoke the method specified by the give method name on the given object instance through reflection.
static <T> Spplr<T>	reflectionSupplier(java.lang.Object instance, java.lang.String methodName, java.lang.Class<T> suppliedClass) Create a supplier that will invoke the method specified by the give method name on the given object instance through reflection.
static <T> Spplr<T>	reflectionSupplier(java.lang.Object instance, java.lang.String methodName, java.lang.Class<T> primaryClass, java.lang.Class<T> secondaryClass) Similar to reflectionSupplier(Object, String, Class), except allows for an alternative return type.

Methods inherited from class java.lang.Object

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

Method Detail

of

public static <T> Spplr<T> of(T value)

Create a supplier that will return the given value.

Type Parameters:

T - Value type.

Parameters:

value - Value to return.

Returns:

A Spplr that will return the given constant value.

map

public static <T,R> Spplr<R> map(@NonNull
                                 Spplr<T> supplier,
                                 @NonNull
                                 Func<T,R> function)

Create a supplier that will transform the value returned by the given supplier by invoking the given function on it. This operation is also known as 'map'. If the given supplier is a const supplier type (supplies a constant or cache value), the returned supplier will also cache the result of the transformation and not re-calculate it on every call.

Type Parameters:

T - Supplied value type.

R - Transformed value type.

Parameters:

supplier - Supplier to transform.

function - Function to transform the supplier with.

Returns:

A Spplr that will apply the given function to the value supplied by the given supplier.

cache

public static <T> Spplr<T> cache(@NonNull
                                 Spplr<T> supplier)

Wrap the given supplier in a supplier that will only call the underlying supplier once, and then cache the returned value. The following calls will returned the cached value. A 'lazy supplier' of sorts.

Type Parameters:

T - Supplied value type.

Parameters:

supplier - Supplier to cache.

Returns:

A Spplr that will call the wrapped supplier once and only once and cache the value for future calls.

reflectionSupplier

public static <T> Spplr<T> reflectionSupplier(@NonNull
                                              java.lang.Object instance,
                                              @NonNull
                                              java.lang.String methodName,
                                              @NonNull
                                              java.lang.Class<T> suppliedClass)

Create a supplier that will invoke the method specified by the give method name on the given object instance through reflection. The method must be no-args and must return a value of the specified type. The method may be private, in which case it will be made accessible outside it's class.

Type Parameters:

T - Supplier return type.

Parameters:

instance - Instance to invoke the method one.

methodName - Method name to invoke. Method must be no-args and return a value of the specified type.

suppliedClass - Expected return type of the method.

Returns:

A Spplr that will invoke the no-args method specified by the given name on the given instance.

reflectionSupplier

public static <T> Spplr<T> reflectionSupplier(java.lang.Object instance,
                                              java.lang.String methodName,
                                              java.lang.Class<T> primaryClass,
                                              java.lang.Class<T> secondaryClass)

Similar to reflectionSupplier(Object, String, Class), except allows for an alternative return type. Will first try to create a reflection supplier using the primary class, but if that fails (the method doesn't return the primary class), will re-try with the secondary class. Useful for cases where the return type could be either a primitive or the primitive's boxed version (i.e. Integer.type or Integer.class).

Type Parameters:

T - Supplier return type.

Parameters:

instance - Instance to invoke the method one.

methodName - Method name to invoke. Method must be no-args and return a value of either the primary class or the secondary type.

primaryClass - Primary return type of the method. Will be tried first.

secondaryClass - Secondary return type of the method. Will be tried if the method doesn't return the primary type.

Returns:

A Spplr that will invoke the no-args method specified by the given name on the given instance.

reflectionListSupplier

public static <T> Spplr<java.util.List<T>> reflectionListSupplier(java.lang.Object instance,
                                                                  java.lang.String methodName,
                                                                  java.lang.Class<T[]> suppliedClass)

Create a supplier that will invoke the method specified by the give method name on the given object instance through reflection. The created supplier will supply a List of values. The method must be no-args and must return an array of the specified type. The method may be private, in which case it will be made accessible outside it's class.

Type Parameters:

T - Supplier return type.

Parameters:

instance - Instance to invoke the method one.

methodName - Method name to invoke. Method must be no-args and return an array of the specified type.

suppliedClass - Expected array return type of the method.

Returns:

A Spplr that will invoke the no-args method specified by the given name on the given instance.