diff --git a/build/shared/revisions.txt b/build/shared/revisions.txt
index 0ed683c7c..05c4f3526 100644
--- a/build/shared/revisions.txt
+++ b/build/shared/revisions.txt
@@ -57,6 +57,12 @@ Not quite ready for prime time, however.
 
 + Added StringList(Object...) constructor to handle a grab bag of objects
 
++ Added appendUnique() to Int/Float/StringList to only add unique items
+  to a list. Replaces the following code, making "set" operations easier:
+  if (!theList.hasValue(value)) {
+    thiList.append(value);
+  }
+
 + Inside main(), don't set 'args' to a zero-length array if no args 
   were passed in, instead leave 'args' null. 
 
diff --git a/core/src/processing/data/FloatList.java b/core/src/processing/data/FloatList.java
index bc39a3ae3..5862cc7c8 100644
--- a/core/src/processing/data/FloatList.java
+++ b/core/src/processing/data/FloatList.java
@@ -285,6 +285,14 @@ public class FloatList implements Iterable<Float> {
   }
 
 
+  /** Add this value, but only if it's not already in the list. */
+  public void appendUnique(float value) {
+    if (!hasValue(value)) {
+      append(value);
+    }
+  }
+
+
 //  public void insert(int index, int value) {
 //    if (index+1 > count) {
 //      if (index+1 < data.length) {
diff --git a/core/src/processing/data/IntList.java b/core/src/processing/data/IntList.java
index e9a310361..c90390eba 100644
--- a/core/src/processing/data/IntList.java
+++ b/core/src/processing/data/IntList.java
@@ -254,6 +254,14 @@ public class IntList implements Iterable<Integer> {
   }
 
 
+  /** Add this value, but only if it's not already in the list. */
+  public void appendUnique(int value) {
+    if (!hasValue(value)) {
+      append(value);
+    }
+  }
+
+
 //  public void insert(int index, int value) {
 //    if (index+1 > count) {
 //      if (index+1 < data.length) {
diff --git a/core/src/processing/data/StringList.java b/core/src/processing/data/StringList.java
index 42f807cee..a647a9191 100644
--- a/core/src/processing/data/StringList.java
+++ b/core/src/processing/data/StringList.java
@@ -314,6 +314,14 @@ public class StringList implements Iterable<String> {
   }
 
 
+  /** Add this value, but only if it's not already in the list. */
+  public void appendUnique(String value) {
+    if (!hasValue(value)) {
+      append(value);
+    }
+  }
+
+
 //  public void insert(int index, int value) {
 //    if (index+1 > count) {
 //      if (index+1 < data.length) {
diff --git a/core/todo.txt b/core/todo.txt
index 196883fe6..70c27a1f4 100644
--- a/core/todo.txt
+++ b/core/todo.txt
@@ -38,6 +38,7 @@ X   this was fixed earlier?
 X fix flicker when resizing window 
 X   running through PSurfaceAWT.setSize() is probably overkill
 o   setLocationRelativeTo(null) was removed, will it be missed?
+X add appendUnique() to Int/Float/StringList
 
 opengl
 X OpenGL sketches work only after running a sketch with default renderer
@@ -193,7 +194,6 @@ _   map() is bad for Python and JavaScript
 
 
 data
-_ add appendUnique()
 _ add fromOrder() and others? otherwise need temp object:
 _   categoryIndexLookup = new StringList(flavors).getOrder();
 _ handling of 'missing' values in Table needs serious work