rwaldhoff 2003/11/25 11:21:43
Modified: functor/src/java/org/apache/commons/functor Algorithms.java
functor/src/test/org/apache/commons/functor
TestAlgorithms.java
Log:
iterate lazily, using TransformedIterator and FilteredIterator
Revision Changes Path
1.10 +27 -24
jakarta-commons-sandbox/functor/src/java/org/apache/commons/functor/Algorithms.java
Index: Algorithms.java
===================================================================
RCS file:
/home/cvs/jakarta-commons-sandbox/functor/src/java/org/apache/commons/functor/Algorithms.java,v
retrieving revision 1.9
retrieving revision 1.10
diff -u -r1.9 -r1.10
--- Algorithms.java 25 Nov 2003 18:34:13 -0000 1.9
+++ Algorithms.java 25 Nov 2003 19:21:43 -0000 1.10
@@ -60,6 +60,9 @@
import java.util.Iterator;
import java.util.NoSuchElementException;
+import org.apache.commons.functor.core.collection.FilteredIterator;
+import org.apache.commons.functor.core.collection.TransformedIterator;
+import org.apache.commons.functor.core.composite.UnaryNot;
import org.apache.commons.functor.generator.BaseGenerator;
import org.apache.commons.functor.generator.Generator;
import org.apache.commons.functor.generator.IteratorToGeneratorAdapter;
@@ -87,11 +90,11 @@
public class Algorithms {
/**
- * Equivalent to
- * <code>[EMAIL PROTECTED] #apply(Generator,UnaryFunction) apply}(new [EMAIL
PROTECTED] org.apache.commons.functor.generator.IteratorToGeneratorAdapter
IteratorToGeneratorAdapter}(iter),func).toCollection().iterator()</code>.
+ * Returns an [EMAIL PROTECTED] Iterator} that will apply the given [EMAIL
PROTECTED] UnaryFunction} to each
+ * element when accessed.
*/
public static final Iterator apply(Iterator iter, UnaryFunction func) {
- return apply(new
IteratorToGeneratorAdapter(iter),func).toCollection().iterator();
+ return TransformedIterator.transform(iter,func);
}
/**
@@ -259,13 +262,12 @@
return result[0];
}
-
/**
- * Equivalent to
- * <code>[EMAIL PROTECTED] #reject(Generator,UnaryPredicate) reject}(new [EMAIL
PROTECTED] org.apache.commons.functor.generator.IteratorToGeneratorAdapter
IteratorToGeneratorAdapter}(iter),pred).toCollection().iterator()</code>.
+ * Returns an [EMAIL PROTECTED] Iterator} that will only return elements that DO
+ * NOT match the given predicate.
*/
public static Iterator reject(Iterator iter, UnaryPredicate pred) {
- return reject(new IteratorToGeneratorAdapter(iter),
pred).toCollection().iterator();
+ return FilteredIterator.filter(iter,UnaryNot.not(pred));
}
/**
@@ -287,11 +289,11 @@
}
/**
- * Equivalent to
- * <code>[EMAIL PROTECTED] #select(Generator,UnaryPredicate) select}(new [EMAIL
PROTECTED] org.apache.commons.functor.generator.IteratorToGeneratorAdapter
IteratorToGeneratorAdapter}(iter),pred).toCollection().iterator()</code>.
+ * Returns an [EMAIL PROTECTED] Iterator} that will only return elements that DO
+ * match the given predicate.
*/
public static final Iterator select(Iterator iter, UnaryPredicate pred) {
- return select(new IteratorToGeneratorAdapter(iter),
pred).toCollection().iterator();
+ return FilteredIterator.filter(iter,pred);
}
/**
@@ -314,24 +316,24 @@
/**
* Equivalent to
- * <code>[EMAIL PROTECTED] #until(Generator,UnaryPredicate) until}(new [EMAIL
PROTECTED] org.apache.commons.functor.generator.IteratorToGeneratorAdapter
IteratorToGeneratorAdapter}(iter),pred).toCollection().iterator()</code>.
+ * <code>[EMAIL PROTECTED] #reject(Iterator,UnaryPredicate)
reject}(iter,pred)</code>.
*/
- public static final Iterator until(Iterator iter, UnaryPredicate pred) {
- return until(new IteratorToGeneratorAdapter(iter),
pred).toCollection().iterator();
+ public static final Iterator until(final Iterator iter, final UnaryPredicate
pred) {
+ return reject(iter,pred);
}
/**
- * Returns a [EMAIL PROTECTED] Generator} that will stop when the predicate
becomes
- * true. This is useful for imposing [EMAIL PROTECTED] Generator} limits. For
example:
- *
- * <pre>
- * EachLine.open(file).until(new Offset(1));
- * </pre>
- *
- * Would only "generate" 1 line from the file before [EMAIL PROTECTED]
Generator#stop
- * stopping} the generator.
+ * Equivalent to
+ * <code>[EMAIL PROTECTED] #reject(Generator,UnaryPredicate)
reject}(gen,pred)</code>.
*/
public static final Generator until(final Generator gen, final UnaryPredicate
pred) {
+ return reject(gen,pred);
+ // here's the old version of this code
+ // reject(gen,pred) doesn't call stop()
+ // like this version does.
+ // should reject call stop?
+ // is the stop call signficant here?
+ /*
return new BaseGenerator(gen) {
public void run(final UnaryProcedure proc) {
gen.run(new UnaryProcedure() {
@@ -345,6 +347,7 @@
});
}
};
+ */
}
/**
1.6 +2 -3
jakarta-commons-sandbox/functor/src/test/org/apache/commons/functor/TestAlgorithms.java
Index: TestAlgorithms.java
===================================================================
RCS file:
/home/cvs/jakarta-commons-sandbox/functor/src/test/org/apache/commons/functor/TestAlgorithms.java,v
retrieving revision 1.5
retrieving revision 1.6
diff -u -r1.5 -r1.6
--- TestAlgorithms.java 25 Nov 2003 18:34:13 -0000 1.5
+++ TestAlgorithms.java 25 Nov 2003 19:21:43 -0000 1.6
@@ -218,7 +218,6 @@
public void testLimit() {
Collection col =
IteratorToGeneratorAdapter.adapt(Algorithms.until(list.iterator(), new
Offset(2))).toCollection();
- System.out.println(col);
assertEquals("[0, 1]", col.toString());
}
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