diff --git a/src/capnp/PointerBuilder.java b/src/capnp/PointerBuilder.java
index 9c7ec75..f461ed9 100644
--- a/src/capnp/PointerBuilder.java
+++ b/src/capnp/PointerBuilder.java
@@ -8,4 +8,10 @@ public final class PointerBuilder {
         this.segment = segment;
         this.pointer = pointer;
     }
+
+    public final ListBuilder initStructList(int elementCount, StructSize elementSize) {
+        return WireHelpers.initStructListPointer(this.pointer, this.segment, elementCount, elementSize);
+    }
+
+
 }
diff --git a/src/capnp/StructSize.java b/src/capnp/StructSize.java
index 7539e0f..21a5125 100644
--- a/src/capnp/StructSize.java
+++ b/src/capnp/StructSize.java
@@ -1,8 +1,8 @@
 package org.capnproto;
 
 public final class StructSize {
-    public final short data;
-    public final short pointers;
+    public final short data;      // number of words in data section
+    public final short pointers;  // number of words in pointer section
     public final byte preferredListEncoding;
 
     public StructSize(short data, short pointers, byte preferredListEncoding) {
@@ -10,4 +10,9 @@ public final class StructSize {
         this.pointers = pointers;
         this.preferredListEncoding = preferredListEncoding;
     }
+
+    public final int total() {
+        return (int)this.data + (int)this.pointers;
+    }
+
 }
diff --git a/src/capnp/WireHelpers.java b/src/capnp/WireHelpers.java
index 76cf8cd..c4c4fb1 100644
--- a/src/capnp/WireHelpers.java
+++ b/src/capnp/WireHelpers.java
@@ -2,12 +2,38 @@ package org.capnproto;
 
 final class WireHelpers {
 
+    public static ListBuilder initListPointer(int refOffset,
+                                              SegmentBuilder segment,
+                                              int elementCount,
+                                              byte elementSize) {
+        throw new Error("unimplemented");
+    }
+
+    public static ListBuilder initStructListPointer(int refOffset,
+                                                    SegmentBuilder segment,
+                                                    int elementCount,
+                                                    StructSize elementSize) {
+        if (elementSize.preferredListEncoding != FieldSize.INLINE_COMPOSITE) {
+            //# Small data-only struct. Allocate a list of primitives instead.
+            return initListPointer(refOffset, segment, elementCount,
+                                   elementSize.preferredListEncoding);
+        }
+
+        int wordsPerElement = elementSize.total();
+
+        throw new Error("unimplemented");
+    }
+
     public static StructReader readStructPointer(SegmentReader segment,
                                                  int refOffset,
                                                  int nestingLimit) {
 
         // TODO error handling
 
+        if (nestingLimit < 0) {
+            throw new DecodeException("Message is too deeply nested or contains cycles.");
+        }
+
         long ref = WirePointer.get(segment.buffer, refOffset);
         int ptrOffset = WirePointer.target(refOffset, ref);
         int structPtr = WirePointer.structPointer(ref);
@@ -78,6 +104,12 @@ final class WireHelpers {
     public static Text.Reader readTextPointer(SegmentReader segment,
                                               int refOffset) {
         long ref = WirePointer.get(segment.buffer, refOffset);
+
+        if (WirePointer.isNull(ref)) {
+            // XXX should use the default value
+            return new Text.Reader(java.nio.ByteBuffer.wrap(new byte[0]), 0, 0);
+        }
+
         int ptrOffset = WirePointer.target(refOffset, ref);
         int listPtr = WirePointer.listPointer(ref);
         int size = ListPointer.elementCount(listPtr);
@@ -93,7 +125,7 @@ final class WireHelpers {
         // TODO bounds check?
 
         if (size == 0 || segment.buffer.get(8 * ptrOffset + size - 1) != 0) {
-            throw new DecodeException("Message containts text that is not NUL-terminated.");
+            throw new DecodeException("Message contains text that is not NUL-terminated.");
         }
 
         return new Text.Reader(segment.buffer, ptrOffset, size - 1);