diff --git a/Changelog.md b/Changelog.md
new file mode 100644
--- /dev/null
+++ b/Changelog.md
@@ -0,0 +1,9 @@
+# Revision history for fast-myers-diff
+
+## 0.0.2 -- 2025-01-15
+
+- Edit distance functions
+
+## 0.0.1 -- 2024-09-08
+
+- Added `NFData` instance for `PolyDiff`
diff --git a/fast-myers-diff.cabal b/fast-myers-diff.cabal
--- a/fast-myers-diff.cabal
+++ b/fast-myers-diff.cabal
@@ -1,16 +1,16 @@
 cabal-version: 1.12
 
--- This file has been generated from package.yaml by hpack version 0.35.2.
+-- This file has been generated from package.yaml by hpack version 0.36.1.
 --
 -- see: https://github.com/sol/hpack
 
 name:           fast-myers-diff
-version:        0.0.0
+version:        0.0.2
 synopsis:       A fast implementation of the Myers diff algorithm.
 description:    A fast implementation of the diffing algorithm described in 'An O(ND) Difference Algorithm and Its Variations' by Eugene W. Myers.
 category:       Testing
-homepage:       https://github.com/NorfairKing/sydtest#readme
-bug-reports:    https://github.com/NorfairKing/sydtest/issues
+homepage:       https://github.com/NorfairKing/fast-myers-diff#readme
+bug-reports:    https://github.com/NorfairKing/fast-myers-diff/issues
 author:         Tom Sydney Kerckhove
 maintainer:     syd@cs-syd.eu
 copyright:      Copyright (c) 2023 Tom Sydney Kerckhove
@@ -19,10 +19,11 @@
 build-type:     Simple
 extra-source-files:
     LICENSE
+    Changelog.md
 
 source-repository head
   type: git
-  location: https://github.com/NorfairKing/sydtest
+  location: https://github.com/NorfairKing/fast-myers-diff
 
 library
   exposed-modules:
@@ -33,6 +34,7 @@
       src
   build-depends:
       base >=4.7 && <5
+    , deepseq
     , dlist
     , text
     , vector
diff --git a/src/Myers/Diff.hs b/src/Myers/Diff.hs
--- a/src/Myers/Diff.hs
+++ b/src/Myers/Diff.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE DeriveAnyClass #-}
+{-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE ScopedTypeVariables #-}
@@ -20,6 +22,12 @@
     getVectorDiffBy,
     getGroupedVectorDiffBy,
 
+    -- * Distance
+    getTextEditDistance,
+    getStringEditDistance,
+    getEditDistance,
+    getEditDistanceBy,
+
     -- ** Internals
     Edit (..),
     getEditScript,
@@ -35,6 +43,7 @@
   )
 where
 
+import Control.DeepSeq (NFData)
 import Control.Monad
 import Control.Monad.ST
 import Data.DList (DList)
@@ -48,6 +57,7 @@
 import qualified Data.Vector as V
 import Data.Vector.Mutable (MVector)
 import qualified Data.Vector.Mutable as MV
+import GHC.Generics
 
 type Diff a = PolyDiff a a
 
@@ -59,7 +69,7 @@
 -- of equality that doesn't check all data (for example, if you are using a
 -- custom equality relation to only perform equality on side of a tuple).
 data PolyDiff a b = First a | Second b | Both a b
-  deriving (Show, Eq)
+  deriving (Show, Eq, Generic, NFData)
 
 bimapPolyDiff :: (a -> c) -> (b -> d) -> PolyDiff a b -> PolyDiff c d
 bimapPolyDiff f g = \case
@@ -70,7 +80,7 @@
 -- |
 --
 -- For backward compatibility with 'Diff', use more specific functions if you can.
-getDiff :: Eq a => [a] -> [a] -> [Diff a]
+getDiff :: (Eq a) => [a] -> [a] -> [Diff a]
 getDiff = getDiffBy (==)
 
 -- |
@@ -82,7 +92,7 @@
 -- |
 --
 -- For backward compatibility with 'Diff', use more specific functions if you can.
-getGroupedDiff :: Eq a => [a] -> [a] -> [Diff [a]]
+getGroupedDiff :: (Eq a) => [a] -> [a] -> [Diff [a]]
 getGroupedDiff = getGroupedDiffBy (==)
 
 -- |
@@ -120,7 +130,7 @@
 -- | Diff two 'Vector's
 --
 -- Prefer 'getGroupedVectorDiff' for performance reasons.
-getVectorDiff :: Eq a => Vector a -> Vector a -> Vector (Diff a)
+getVectorDiff :: (Eq a) => Vector a -> Vector a -> Vector (Diff a)
 getVectorDiff = getVectorDiffBy (==)
 
 -- | Diff two 'Vector's with different types using a custom equality operator
@@ -130,15 +140,39 @@
 getVectorDiffBy eq old new = computeDiffFromEditScript old new (getEditScriptBy eq old new)
 
 -- | Diff two 'Vector's with grouped results
-getGroupedVectorDiff :: Eq a => Vector a -> Vector a -> Vector (Diff (Vector a))
+getGroupedVectorDiff :: (Eq a) => Vector a -> Vector a -> Vector (Diff (Vector a))
 getGroupedVectorDiff = getGroupedVectorDiffBy (==)
 
 -- | Diff two 'Vector's with grouped results using a custom equality operator
 getGroupedVectorDiffBy :: forall a b. (a -> b -> Bool) -> Vector a -> Vector b -> Vector (PolyDiff (Vector a) (Vector b))
 getGroupedVectorDiffBy eq old new = computeGroupedDiffFromEditScript old new (getEditScriptBy eq old new)
 
+-- | 'Text edit distance
+getTextEditDistance :: Text -> Text -> Word
+getTextEditDistance actual expected = getStringEditDistance (T.unpack actual) (T.unpack expected)
+
+-- | 'String' edit distance
+getStringEditDistance :: String -> String -> Word
+getStringEditDistance actual expected = getEditDistance (V.fromList actual) (V.fromList expected)
+
+-- | Compute the total size of the edit script vector from 'getEditScript.
+getEditDistance :: (Eq a) => Vector a -> Vector a -> Word
+getEditDistance = getEditDistanceBy (==)
+
+-- | Compute the total size of the edit script vector from 'getEditScriptBy'.
+getEditDistanceBy :: (a -> b -> Bool) -> Vector a -> Vector b -> Word
+getEditDistanceBy eq old new =
+  -- This 'fromIntegral' is safe because you'd need a ridiculously large edit
+  -- script for it to cause trouble, and that would crash the program before
+  -- 'fromIntegral' could.
+  (fromIntegral :: Int -> Word) $ sum $ V.map editCost $ getEditScriptBy eq old new
+  where
+    editCost = \case
+      Delete _ c -> c
+      Insert _ _ c -> c
+
 -- | Compute the edit script to turn a given 'Vector' into the second given 'Vector'
-getEditScript :: forall a. Eq a => Vector a -> Vector a -> Vector Edit
+getEditScript :: forall a. (Eq a) => Vector a -> Vector a -> Vector Edit
 getEditScript = getEditScriptBy (==)
 
 -- | Compute the edit script to turn a given 'Vector' into the second given 'Vector' with a custom equality relation
@@ -475,18 +509,18 @@
 data Edit
   = -- | Delete from the old vector
     Delete
+      -- position in the old vector
       Int
-      -- ^ position in the old vector
+      -- number of items to delete
       Int
-      -- ^ number of items to delete
   | -- | Insert into the old vector
     Insert
+      -- position in the old vector
       Int
-      -- ^ position in the old vector
+      -- position in the new vector
       Int
-      -- ^ position in the new vector
+      -- number of items to insert
       Int
-      -- ^ number of items to insert
   deriving (Show, Eq, Ord)
 
 oldPosition :: Edit -> Int
@@ -508,13 +542,13 @@
 sliceIx start end = V.slice start (end - start)
 
 -- | Short-circuiting monadic (&&)
-(&&.) :: Applicative m => Bool -> m Bool -> m Bool
+(&&.) :: (Applicative m) => Bool -> m Bool -> m Bool
 (&&.) b1 mkB2 = do
   if b1
     then mkB2
     else pure False
 
-forUntilJust :: Monad m => [a] -> (a -> m (Maybe b)) -> m (Maybe b)
+forUntilJust :: (Monad m) => [a] -> (a -> m (Maybe b)) -> m (Maybe b)
 forUntilJust [] _ = pure Nothing
 forUntilJust (a : rest) func = do
   mRes <- func a
diff --git a/test/Main.hs b/test/Main.hs
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -85,6 +85,13 @@
     exampleSpec "foofoo" "foo" [Delete 1 1, Delete 3 1, Delete 5 1] [Both 'f' 'f', First 'o', Both 'o' 'o', First 'f', Both 'o' 'o', First 'o']
     exampleSpec "foo" "foofoo" [Insert 1 1 1, Insert 2 3 1, Insert 3 5 1] [Both 'f' 'f', Second 'o', Both 'o' 'o', Second 'f', Both 'o' 'o', Second 'o']
 
+  describe "getStringEditDistance" $ do
+    prop "is 0 for identical strings" $ \t ->
+      getStringEditDistance t t `shouldBe` 0
+
+    it "returns 6 for these two completely different strings" $
+      getStringEditDistance "abc" "def" `shouldBe` 6
+
   describe "getVectorDiff" $ do
     let exampleSpec :: Vector Char -> Vector Char -> Vector (Diff Char) -> Spec
         exampleSpec old new expected =