diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # Revision history for alex-tools
 
+## 0.1.1.0  -- 2016-09-02
+
+* Add `NFData` instances
+
 ## 0.1.0.0  -- 2016-09-02
 
 * Initial version.
diff --git a/alex-tools.cabal b/alex-tools.cabal
--- a/alex-tools.cabal
+++ b/alex-tools.cabal
@@ -1,5 +1,5 @@
 name:                alex-tools
-version:             0.1.0.0
+version:             0.1.1.0
 synopsis:            A set of functions for a common use case of Alex.
 description:         This captures a common patter for using Alex.
 license:             ISC
@@ -21,6 +21,7 @@
   other-extensions:    TemplateHaskell
   build-depends:       base >=4.7 && <4.10,
                        text >=1.2 && <1.3,
+                       deepseq >=1.3 && <1.5,
                        template-haskell >=2.9.0 && <2.12
   hs-source-dirs:      src
   ghc-options:         -Wall
diff --git a/src/AlexTools.hs b/src/AlexTools.hs
--- a/src/AlexTools.hs
+++ b/src/AlexTools.hs
@@ -5,6 +5,7 @@
   , Lexeme(..)
   , SourcePos(..), startPos, beforeStartPos
   , SourceRange(..)
+  , prettySourcePos, prettySourceRange
   , HasRange(..)
   , (<->)
   , moveSourcePos
@@ -37,6 +38,7 @@
 
   ) where
 
+import           Control.DeepSeq
 import           Data.Word(Word8)
 import           Data.Text(Text)
 import qualified Data.Text as Text
@@ -52,12 +54,22 @@
   , lexemeRange :: !SourceRange
   } deriving (Show, Eq)
 
+instance NFData t => NFData (Lexeme t) where
+  rnf (Lexeme x y z) = rnf (x,y,z)
+
 data SourcePos = SourcePos
   { sourceIndex   :: !Int
   , sourceLine    :: !Int
   , sourceColumn  :: !Int
   } deriving (Show, Eq)
 
+prettySourcePos :: SourcePos -> String
+prettySourcePos x = show (sourceLine x) ++ ":" ++ show (sourceColumn x)
+
+
+instance NFData SourcePos where
+  rnf (SourcePos x y z) = rnf (x,y,z)
+
 -- | Update a 'SourcePos' for a particular matched character
 moveSourcePos :: Char -> SourcePos -> SourcePos
 moveSourcePos c p = SourcePos { sourceIndex  = sourceIndex p + 1
@@ -80,6 +92,13 @@
   , sourceTo   :: !SourcePos
   } deriving (Show, Eq)
 
+prettySourceRange :: SourceRange -> String
+prettySourceRange x = prettySourcePos (sourceFrom x) ++ "--" ++
+                      prettySourcePos (sourceTo x)
+
+instance NFData SourceRange where
+  rnf (SourceRange x y) = rnf (x,y)
+
 class HasRange t where
   range :: t -> SourceRange
 
@@ -225,7 +244,7 @@
 
 
 -- | Generate a function to use an Alex lexer.
--- The expression is of type @LexerConfig s t -> Input -> s -> [Lexeme t]@
+-- The expression is of type @LexerConfig s t -> Input -> [Lexeme t]@
 makeLexer :: ExpQ
 makeLexer =
   do let local = do n <- newName "x"