1 files changed, 22 insertions, 0 deletions
diff --git a/src/main/java/pl/edu/mimuw/cloudatlas/model/ValueUtils.java b/src/main/java/pl/edu/mimuw/cloudatlas/model/ValueUtils.java
index 866349f..20d6600 100644
--- a/src/main/java/pl/edu/mimuw/cloudatlas/model/ValueUtils.java
+++ b/src/main/java/pl/edu/mimuw/cloudatlas/model/ValueUtils.java
@@ -1,5 +1,8 @@
 package pl.edu.mimuw.cloudatlas.model;
 
+import java.util.List;
+import java.util.Iterator;
+
 public class ValueUtils {
     public static boolean valueNonNullOfType(Value value, Type type) {
         return value != null && !value.isNull() && value.getType().isCompatible(type);
@@ -16,4 +19,23 @@ public class ValueUtils {
     public static ValueTime addToTime(ValueTime time, long millis) {
         return time.addValue(new ValueDuration(millis));
     }
+
+    public static boolean isPrefix(PathName prefix, PathName path) {
+        List<String> prefixComponents = prefix.getComponents();
+        List<String> pathComponents = path.getComponents();
+
+        if (prefixComponents.size() > pathComponents.size()) {
+            return false;
+        }
+
+        Iterator<String> prefixIterator = prefixComponents.iterator();
+        Iterator<String> pathIterator = pathComponents.iterator();
+
+        while (prefixIterator.hasNext()) {
+            if (!prefixIterator.next().equals(pathIterator.next())) {
+                return false;
+            }
+        }
+        return true;
+    }
 }