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Posted to commits@commons.apache.org by ba...@apache.org on 2009/09/15 07:55:06 UTC
svn commit: r815048 -
/commons/proper/collections/trunk/src/java/org/apache/commons/collections/functors/FunctorUtils.java
Author: bayard
Date: Tue Sep 15 05:55:06 2009
New Revision: 815048
URL: http://svn.apache.org/viewvc?rev=815048&view=rev
Log:
Merging from -r468106:814127 of collections_jdk5_branch - namely where this code was generified; mostly in r738956.
Also see the following revisions:
------------------------------------------------------------------------
r641231 | skestle | 2008-03-26 02:58:51 -0700 (Wed, 26 Mar 2008) | 1 line
Started incorporating Edwin's patch for COLLECTIONS-253, in preparation for COLLECTIONS-290.
------------------------------------------------------------------------
Modified:
commons/proper/collections/trunk/src/java/org/apache/commons/collections/functors/FunctorUtils.java
Modified: commons/proper/collections/trunk/src/java/org/apache/commons/collections/functors/FunctorUtils.java
URL: http://svn.apache.org/viewvc/commons/proper/collections/trunk/src/java/org/apache/commons/collections/functors/FunctorUtils.java?rev=815048&r1=815047&r2=815048&view=diff
==============================================================================
--- commons/proper/collections/trunk/src/java/org/apache/commons/collections/functors/FunctorUtils.java (original)
+++ commons/proper/collections/trunk/src/java/org/apache/commons/collections/functors/FunctorUtils.java Tue Sep 15 05:55:06 2009
@@ -17,7 +17,6 @@
package org.apache.commons.collections.functors;
import java.util.Collection;
-import java.util.Iterator;
import org.apache.commons.collections.Closure;
import org.apache.commons.collections.Predicate;
@@ -33,33 +32,53 @@
* @author Matt Benson
*/
class FunctorUtils {
-
+
/**
* Restricted constructor.
*/
private FunctorUtils() {
super();
}
-
+
/**
* Clone the predicates to ensure that the internal reference can't be messed with.
- *
+ * Due to the {@link Predicate#evaluate(T)} method, Predicate<? super T> is
+ * able to be coerced to Predicate<T> without casting issues.
+ *
* @param predicates the predicates to copy
* @return the cloned predicates
*/
- static Predicate[] copy(Predicate[] predicates) {
+ @SuppressWarnings("unchecked")
+ static <T> Predicate<T>[] copy(Predicate<? super T>[] predicates) {
if (predicates == null) {
return null;
}
- return (Predicate[]) predicates.clone();
+ return (Predicate<T>[]) predicates.clone();
+ }
+
+ /**
+ * A very simple method that coerces Predicate<? super T> to Predicate<T>.
+ * Due to the {@link Predicate#evaluate(T)} method, Predicate<? super T> is
+ * able to be coerced to Predicate<T> without casting issues.
+ * <p>This method exists
+ * simply as centralised documentation and atomic unchecked warning
+ * suppression.
+ *
+ * @param <T> the type of object the returned predicate should "accept"
+ * @param predicate the predicate to coerce.
+ * @return the coerced predicate.
+ */
+ @SuppressWarnings("unchecked")
+ static <T> Predicate<T> coerce(Predicate<? super T> predicate){
+ return (Predicate<T>) predicate;
}
-
+
/**
* Validate the predicates to ensure that all is well.
- *
+ *
* @param predicates the predicates to validate
*/
- static void validate(Predicate[] predicates) {
+ static void validate(Predicate<?>[] predicates) {
if (predicates == null) {
throw new IllegalArgumentException("The predicate array must not be null");
}
@@ -69,22 +88,23 @@
}
}
}
-
+
/**
* Validate the predicates to ensure that all is well.
- *
+ *
* @param predicates the predicates to validate
* @return predicate array
*/
- static Predicate[] validate(Collection predicates) {
+ @SuppressWarnings("unchecked")
+ static <T> Predicate<T>[] validate(Collection<? extends Predicate<T>> predicates) {
if (predicates == null) {
throw new IllegalArgumentException("The predicate collection must not be null");
}
// convert to array like this to guarantee iterator() ordering
- Predicate[] preds = new Predicate[predicates.size()];
+ Predicate<T>[] preds = new Predicate[predicates.size()];
int i = 0;
- for (Iterator it = predicates.iterator(); it.hasNext();) {
- preds[i] = (Predicate) it.next();
+ for (Predicate<T> predicate : predicates) {
+ preds[i] = predicate;
if (preds[i] == null) {
throw new IllegalArgumentException("The predicate collection must not contain a null predicate, index " + i + " was null");
}
@@ -92,26 +112,27 @@
}
return preds;
}
-
+
/**
* Clone the closures to ensure that the internal reference can't be messed with.
- *
+ *
* @param closures the closures to copy
* @return the cloned closures
*/
- static Closure[] copy(Closure[] closures) {
+ @SuppressWarnings("unchecked")
+ static <E> Closure<E>[] copy(Closure<? super E>[] closures) {
if (closures == null) {
return null;
}
- return (Closure[]) closures.clone();
+ return (Closure<E>[]) closures.clone();
}
-
+
/**
* Validate the closures to ensure that all is well.
- *
+ *
* @param closures the closures to validate
*/
- static void validate(Closure[] closures) {
+ static void validate(Closure<?>[] closures) {
if (closures == null) {
throw new IllegalArgumentException("The closure array must not be null");
}
@@ -123,24 +144,40 @@
}
/**
+ * A very simple method that coerces Closure<? super T> to Closure<T>.
+ * <p>This method exists
+ * simply as centralised documentation and atomic unchecked warning
+ * suppression.
+ *
+ * @param <T> the type of object the returned closure should "accept"
+ * @param closure the closure to coerce.
+ * @return the coerced closure.
+ */
+ @SuppressWarnings("unchecked")
+ static <T> Closure<T> coerce(Closure<? super T> closure){
+ return (Closure<T>) closure;
+ }
+
+ /**
* Copy method
- *
+ *
* @param transformers the transformers to copy
* @return a clone of the transformers
*/
- static Transformer[] copy(Transformer[] transformers) {
+ @SuppressWarnings("unchecked")
+ static <I, O> Transformer<I, O>[] copy(Transformer<? super I, ? extends O>[] transformers) {
if (transformers == null) {
return null;
}
- return (Transformer[]) transformers.clone();
+ return (Transformer<I, O>[]) transformers.clone();
}
-
+
/**
* Validate method
- *
+ *
* @param transformers the transformers to validate
*/
- static void validate(Transformer[] transformers) {
+ static void validate(Transformer<?, ?>[] transformers) {
if (transformers == null) {
throw new IllegalArgumentException("The transformer array must not be null");
}
@@ -152,4 +189,19 @@
}
}
+ /**
+ * A very simple method that coerces Transformer<? super I, ? extends O> to Transformer<I, O>.
+ * <p>This method exists
+ * simply as centralised documentation and atomic unchecked warning
+ * suppression.
+ *
+ * @param <T> the type of object the returned transformer should "accept"
+ * @param transformer the transformer to coerce.
+ * @return the coerced transformer.
+ */
+ @SuppressWarnings("unchecked")
+ static <I, O> Transformer<I, O> coerce(Transformer<? super I, ? extends O> transformer) {
+ return (Transformer<I, O>) transformer;
+ }
+
}