6 files changed, 37 insertions, 9 deletions
diff --git a/src/main/java/org/zwobble/mammoth/internal/docx/BodyXmlReader.java b/src/main/java/org/zwobble/mammoth/internal/docx/BodyXmlReader.java
index 2770984..c8cdc1c 100644
--- a/src/main/java/org/zwobble/mammoth/internal/docx/BodyXmlReader.java
+++ b/src/main/java/org/zwobble/mammoth/internal/docx/BodyXmlReader.java
@@ -14,9 +14,9 @@ import java.util.Optional;
 import java.util.Set;
 import java.util.function.Function;
 
-import static com.google.common.collect.Iterables.filter;
 import static org.zwobble.mammoth.internal.docx.ReadResult.EMPTY_SUCCESS;
 import static org.zwobble.mammoth.internal.docx.ReadResult.success;
+import static org.zwobble.mammoth.internal.util.MammothIterables.lazyFilter;
 import static org.zwobble.mammoth.internal.util.MammothLists.list;
 import static org.zwobble.mammoth.internal.util.MammothStrings.trimLeft;
 
@@ -171,7 +171,7 @@ public class BodyXmlReader {
     }
 
     public ReadResult readElements(Iterable<XmlNode> nodes) {
-        return ReadResult.flatMap(filter(nodes, XmlElement.class), this::readElement);
+        return ReadResult.flatMap(lazyFilter(nodes, XmlElement.class), this::readElement);
     }
 
     private ReadResult readParagraph(XmlElement element) {
diff --git a/src/main/java/org/zwobble/mammoth/internal/docx/NotesXmlReader.java b/src/main/java/org/zwobble/mammoth/internal/docx/NotesXmlReader.java
index 235535e..b75df9b 100644
--- a/src/main/java/org/zwobble/mammoth/internal/docx/NotesXmlReader.java
+++ b/src/main/java/org/zwobble/mammoth/internal/docx/NotesXmlReader.java
@@ -7,7 +7,7 @@ import org.zwobble.mammoth.internal.xml.XmlElement;
 
 import java.util.List;
 
-import static com.google.common.collect.Iterables.filter;
+import static org.zwobble.mammoth.internal.util.MammothIterables.lazyFilter;
 
 public class NotesXmlReader {
     public static NotesXmlReader footnote(BodyXmlReader bodyReader) {
@@ -29,7 +29,7 @@ public class NotesXmlReader {
     }
 
     public InternalResult<List<Note>> readElement(XmlElement element) {
-        Iterable<XmlElement> elements = filter(element.findChildren("w:" + tagName), this::isNoteElement);
+        Iterable<XmlElement> elements = lazyFilter(element.findChildren("w:" + tagName), this::isNoteElement);
         return InternalResult.flatMap(elements, this::readNoteElement);
     }
 
diff --git a/src/main/java/org/zwobble/mammoth/internal/docx/StylesXml.java b/src/main/java/org/zwobble/mammoth/internal/docx/StylesXml.java
index 9b468fe..81a16af 100644
--- a/src/main/java/org/zwobble/mammoth/internal/docx/StylesXml.java
+++ b/src/main/java/org/zwobble/mammoth/internal/docx/StylesXml.java
@@ -7,7 +7,7 @@ import org.zwobble.mammoth.internal.xml.XmlElementList;
 import java.util.Map;
 import java.util.Optional;
 
-import static com.google.common.collect.Iterables.filter;
+import static org.zwobble.mammoth.internal.util.MammothIterables.lazyFilter;
 import static org.zwobble.mammoth.internal.util.MammothMaps.entry;
 import static org.zwobble.mammoth.internal.util.MammothMaps.toMap;
 
@@ -21,7 +21,7 @@ public class StylesXml {
 
     private static Map<String, Style> readStyles(XmlElementList styleElements, String styleType) {
         return toMap(
-            filter(styleElements, styleElement -> styleElement.getAttribute("w:type").equals(styleType)),
+            lazyFilter(styleElements, styleElement -> styleElement.getAttribute("w:type").equals(styleType)),
             StylesXml::readStyle);
     }
 
diff --git a/src/main/java/org/zwobble/mammoth/internal/util/MammothIterables.java b/src/main/java/org/zwobble/mammoth/internal/util/MammothIterables.java
index c0231e0..fececa3 100644
--- a/src/main/java/org/zwobble/mammoth/internal/util/MammothIterables.java
+++ b/src/main/java/org/zwobble/mammoth/internal/util/MammothIterables.java
@@ -65,6 +65,29 @@ public class MammothIterables {
         };
     }
 
+    public static <T> Iterable<T> lazyFilter(Iterable<T> iterables, Predicate<T> predicate) {
+        return new Iterable<T>() {
+            @Override
+            public Iterator<T> iterator() {
+                return stream(iterables)
+                    .filter(predicate)
+                    .iterator();
+            }
+        };
+    }
+
+    public static <T, R> Iterable<R> lazyFilter(Iterable<T> iterables, Class<R> clazz) {
+        return new Iterable<R>() {
+            @Override
+            @SuppressWarnings("unchecked")
+            public Iterator<R> iterator() {
+                return (Iterator<R>) stream(iterables)
+                    .filter(clazz::isInstance)
+                    .iterator();
+            }
+        };
+    }
+
     private static <T, R> Iterator<R> map(Iterator<T> iterator, Function<T, R> function) {
         return new Iterator<R>() {
             @Override
diff --git a/src/main/java/org/zwobble/mammoth/internal/util/MammothLists.java b/src/main/java/org/zwobble/mammoth/internal/util/MammothLists.java
index 3519cd2..7f5b83c 100644
--- a/src/main/java/org/zwobble/mammoth/internal/util/MammothLists.java
+++ b/src/main/java/org/zwobble/mammoth/internal/util/MammothLists.java
@@ -6,6 +6,7 @@ import com.google.common.collect.Ordering;
 
 import java.util.List;
 import java.util.function.Function;
+import java.util.function.Predicate;
 import java.util.stream.Collectors;
 
 import static org.zwobble.mammoth.internal.util.MammothIterables.stream;
@@ -35,6 +36,10 @@ public class MammothLists {
         return ImmutableList.copyOf(Iterables.concat(first, second));
     }
 
+    public static <T> List<T> eagerFilter(Iterable<T> iterable, Predicate<T> predicate) {
+        return stream(iterable).filter(predicate).collect(Collectors.toList());
+    }
+
     public static <T, R> List<R> eagerMap(Iterable<T> iterable, Function<T, R> function) {
         return stream(iterable).map(function).collect(Collectors.toList());
     }
diff --git a/src/main/java/org/zwobble/mammoth/internal/xml/XmlElement.java b/src/main/java/org/zwobble/mammoth/internal/xml/XmlElement.java
index f8a94f2..ad6f8f3 100644
--- a/src/main/java/org/zwobble/mammoth/internal/xml/XmlElement.java
+++ b/src/main/java/org/zwobble/mammoth/internal/xml/XmlElement.java
@@ -6,8 +6,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 
-import static com.google.common.collect.Iterables.filter;
 import static org.zwobble.mammoth.internal.util.MammothIterables.getFirst;
+import static org.zwobble.mammoth.internal.util.MammothIterables.lazyFilter;
 import static org.zwobble.mammoth.internal.util.MammothIterables.lazyMap;
 import static org.zwobble.mammoth.internal.util.MammothMaps.lookup;
 
@@ -84,8 +84,8 @@ public class XmlElement implements XmlNode, XmlElementLike {
     }
 
     private Iterable<XmlElement> findChildrenIterable(String name) {
-        return filter(
-            filter(children, XmlElement.class),
+        return lazyFilter(
+            lazyFilter(children, XmlElement.class),
             child -> child.getName().equals(name));
     }
 }