fixes and updated comments

go/types/tuple.go

@@ -177,9 +177,8 @@ func (t Tuple) Get(n uint64) Value {
 	return v
 }
 
-// Set returns a new struct where the field name has been set to value. If name is not an
-// existing field in the struct or the type of value is different from the old value of the
-// struct field a new struct type is created.
+// Set returns a new tuple where the field at index n is set to value. Attempting to use Set on an index that is outside
+// of the bounds will cause a panic.  Use Append to add additional values, not Set.
 func (t Tuple) Set(n uint64, v Value) Tuple {
 	prolog, head, tail, count, found := t.splitFieldsAt(n)
 	if !found {
@@ -235,6 +234,7 @@ func (t Tuple) splitFieldsAt(n uint64) (prolog, head, tail []byte, count uint64,
 	head = dec.buff[fieldsOffset:dec.offset]
 
 	if n != count-1 {
+		dec.skipValue()
 		tail = dec.buff[dec.offset:len(dec.buff)]
 	}
 

go/types/tuple_test.go

@@ -27,7 +27,35 @@ func TestTupleEquality(t *testing.T) {
 		t.Error("Tuples should not be equal")
 	}
 
-	tpl3 := tpl2.Set(0, String("aoeu")).Set(1, Int(-1234)).Set(2, Uint(1234)).Set(idIdx, id)
+	tpl3 := tpl2.Set(idIdx, id).Set(0, String("aoeu")).Set(1, Int(-1234)).Set(2, Uint(1234))
+
+	if !tpl2.Equals(tpl3) {
+		t.Error("")
+	}
+
+	tpl3 = tpl2.Set(0, String("aoeu"))
+
+	if !tpl2.Equals(tpl3) {
+		t.Error("")
+	}
+
+	tpl3 = tpl2.Set(1, Int(-1234))
+
+	if !tpl2.Equals(tpl3) {
+		t.Error("")
+	}
+
+	tpl3 = tpl2.Set(2, Uint(1234))
+
+	if !tpl2.Equals(tpl3) {
+		t.Error("")
+	}
+
+	tpl3 = tpl2.Set(idIdx, id)
+
+	if !tpl2.Equals(tpl3) {
+		t.Error("")
+	}
 
 	if !tpl2.Equals(tpl3) {
 		t.Error("")