diff --git a/README.md b/README.md
index 68a79fb..af7f382 100644
--- a/README.md
+++ b/README.md
@@ -6,27 +6,31 @@
 
     charAt :: Prim.Number -> Prim.String -> Prim.String
 
+    charCodeAt :: Prim.Number -> Prim.String -> Prim.Number
+
+    drop :: Prim.Number -> Prim.String -> Prim.String
+
     fromCharCode :: Prim.Number -> Prim.String
 
     indexOf :: Prim.String -> Prim.String -> Prim.Number
 
-    joinWith :: [Prim.String] -> Prim.String -> Prim.String
+    indexOf' :: Prim.String -> Prim.Number -> Prim.String -> Prim.Number
+
+    joinWith :: Prim.String -> [Prim.String] -> Prim.String
 
     lastIndexOf :: Prim.String -> Prim.String -> Prim.Number
 
+    lastIndexOf' :: Prim.String -> Prim.Number -> Prim.String -> Prim.Number
+
     length :: Prim.String -> Prim.Number
 
     localeCompare :: Prim.String -> Prim.String -> Prim.Number
 
     replace :: Prim.String -> Prim.String -> Prim.String -> Prim.String
 
-    slice :: Prim.Number -> Prim.Number -> Prim.String -> Prim.String
-
     split :: Prim.String -> Prim.String -> [Prim.String]
 
-    substr :: Prim.Number -> Prim.Number -> Prim.String -> Prim.String
-
-    substring :: Prim.Number -> Prim.Number -> Prim.String -> Prim.String
+    take :: Prim.Number -> Prim.String -> Prim.String
 
     toLower :: Prim.String -> Prim.String
 
diff --git a/src/Data/String.purs b/src/Data/String.purs
index bd968d6..f451151 100644
--- a/src/Data/String.purs
+++ b/src/Data/String.purs
@@ -26,6 +26,15 @@ foreign import indexOf
   \  }; \
   \}" :: String -> String -> Number
 
+foreign import indexOf'
+  "function indexOf$prime(x) {\
+  \  return function(startAt) {\
+  \    return function(s) {\
+  \      return s.indexOf(x, startAt);\
+  \    }; \
+  \  }; \
+  \}" :: String -> Number -> String -> Number
+
 foreign import lastIndexOf
   "function lastIndexOf(x) {\
   \  return function(s) {\
@@ -33,6 +42,15 @@ foreign import lastIndexOf
   \  };\
   \}" :: String -> String -> Number
 
+foreign import lastIndexOf'
+  "function lastIndexOf$prime(x) {\
+  \  return function(startAt) {\
+  \    return function(s) {\
+  \      return s.lastIndexOf(x, startAt);\
+  \    }; \
+  \  }; \
+  \}" :: String -> Number -> String -> Number
+
 foreign import length
   "function length(s) {\
   \  return s.length;\