diff --git a/types/src/predicates.rs b/types/src/preds.rs
similarity index 79%
rename from types/src/predicates.rs
rename to types/src/preds.rs
index 28e40cb..f10d347 100644
--- a/types/src/predicates.rs
+++ b/types/src/preds.rs
@@ -1,7 +1,10 @@
-/* types/src/predicates.rs
+/* types/src/preds.rs
  * Eryn Wells <eryn@erynwells.me>
  */
 
+//! This module defines several important predicates for determing what kind of
+//! a thing this Object is.
+
 pub trait IsNull {
     /// Is this thing null?
     fn is_null(&self) -> bool { false }
@@ -33,3 +36,8 @@ pub trait IsNumber {
     /// Should return `true` if this Value is a integer number type.
     fn is_integer(&self) -> bool { false }
 }
+
+pub trait IsPair {
+    /// Should return `true` if this Value is a pair.
+    fn is_pair(&self) -> bool { false }
+}