Added lambda-friendly collection filtering utils in U.

rapidoid · Oct 11, 2015 · 94de88c · 94de88c
1 parent da3af88
commit 94de88c
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diff --git a/...n/java/org/rapidoid/lambda/Predicate.java → ...n/java/org/rapidoid/lambda/Predicate.java b/...n/java/org/rapidoid/lambda/Predicate.java → ...n/java/org/rapidoid/lambda/Predicate.java
diff --git a/rapidoid-u/src/main/java/org/rapidoid/util/U.java b/rapidoid-u/src/main/java/org/rapidoid/util/U.java
@@ -56,6 +56,7 @@
 
 import org.rapidoid.lambda.Dynamic;
 import org.rapidoid.lambda.Mapper;
+import org.rapidoid.lambda.Predicate;
 
 /**
  * @author Nikolche Mihajlovski
@@ -1031,4 +1032,32 @@ public static boolean exists(Callable<?> accessChain) {
 		}
 	}
 
+	public static <T> List<T> filter(List<T> items, Predicate<T> predicate) {
+		List<T> filtered = list();
+		addIf(items, filtered, predicate);
+		return filtered;
+	}
+
+	public static <T> Set<T> filter(Set<T> items, Predicate<T> predicate) {
+		Set<T> filtered = set();
+		addIf(items, filtered, predicate);
+		return filtered;
+	}
+
+	public static <T> void addIf(Collection<T> src, Collection<T> dest, Predicate<T> predicate) {
+		for (T item : src) {
+			boolean shouldAdd;
+
+			try {
+				shouldAdd = predicate.eval(item);
+			} catch (Exception e) {
+				throw rte(e);
+			}
+
+			if (shouldAdd) {
+				dest.add(item);
+			}
+		}
+	}
+
 }