2 files changed, 6 insertions, 6 deletions
diff --git a/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java b/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java
index fb344e0..a1bbda6 100644
--- a/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java
+++ b/src/main/java/org/zwobble/couscous/ast/visitors/NodeTransformer.java
@@ -1,9 +1,7 @@
 package org.zwobble.couscous.ast.visitors;
 
-import com.google.common.base.Function;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.Iterables;
 import org.zwobble.couscous.ast.*;
 import org.zwobble.couscous.types.ScalarType;
 import org.zwobble.couscous.types.Type;
@@ -14,7 +12,9 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
 
+import static org.zwobble.couscous.util.ExtraIterables.lazyMap;
 import static org.zwobble.couscous.util.ExtraLists.*;
 
 public class NodeTransformer {
@@ -233,10 +233,10 @@ public class NodeTransformer {
     }
 
     private <T> Set<T> transformSet(Set<T> values, Function<T, T> function) {
-        return ImmutableSet.copyOf(Iterables.transform(values, function));
+        return ImmutableSet.copyOf(lazyMap(values, function));
     }
 
     private <T> List<T> transformList(List<? extends T> values, Function<T, T> function) {
-        return ImmutableList.copyOf(Iterables.transform(values, function));
+        return ImmutableList.copyOf(lazyMap(values, function));
     }
 }
diff --git a/src/main/java/org/zwobble/couscous/util/ExtraIterables.java b/src/main/java/org/zwobble/couscous/util/ExtraIterables.java
index 3881d29..a40b409 100644
--- a/src/main/java/org/zwobble/couscous/util/ExtraIterables.java
+++ b/src/main/java/org/zwobble/couscous/util/ExtraIterables.java
@@ -110,7 +110,7 @@ public class ExtraIterables {
         return Optional.empty();
     }
 
-    public static <T, R> Iterable<R> lazyMap(Iterable<T> iterable, Function<T, R> function) {
+    public static <T, R> Iterable<R> lazyMap(Iterable<? extends T> iterable, Function<T, R> function) {
         return new Iterable<R>() {
             @Override
             public Iterator<R> iterator() {
@@ -119,7 +119,7 @@ public class ExtraIterables {
         };
     }
 
-    private static <T, R> Iterator<R> map(Iterator<T> iterator, Function<T, R> function) {
+    private static <T, R> Iterator<R> map(Iterator<? extends T> iterator, Function<T, R> function) {
         return new Iterator<R>() {
             @Override
             public boolean hasNext() {