Code cleanup, changelog added

CHANGELOG.md

+# Changelog
+
+## [0.1.5] - 2023-11-09
+
+### Changed
+
+- Code cleanup
+
+## [0.1.4] - 2023-11-09
+
+### Fixed
+
+- Hash is still incorrect because of overflowing (`UInt64` range vs
+  `modulus`). I removed `modulus` and just used the overflow
+  functionality of `UInt64`.
+
+## [0.1.3] - 2023-11-08
+
+### Fixed
+
+- Hash was computed incorrectly. I changed to `UInt64` and added tests
+  with `SmallInt`.

src/Data/String/Search/KarpRabin.purs

@@ -25,15 +25,11 @@ module Data.String.Search.KarpRabin (
                                   , fromCodePoint
                                   , Base
                                   , universalBase
-                                  , Modulus
-                                  -- , universalModulus
                                   , Hash
                                   , HashStruct
                                   , hashStruct
                                   , RollingHash
                                   , mkRollingHash
-                                  -- , hashRH
-                                  -- , rehashRH
                                   , hashU64
                                   , rehashU64
                                   ) where
@@ -60,7 +56,6 @@ import Prelude
 
 
 type Base = UInt64
-type Modulus = UInt64
 type Hash = UInt64
 
 
@@ -68,12 +63,6 @@ type Hash = UInt64
 universalBase :: Base
 universalBase = unsafeFromInt 256
 
--- | Modulus that we will use in Karp-Rabin
--- https://www.wolframalpha.com/input?i=prime+number+greater+than+50000000
--- universalModulus :: Modulus
--- universalModulus = unsafeFromInt 1009
--- universalModulus = unsafeFromInt 50000017
-
 
 fromCodePoint :: CodePoint -> Base
 fromCodePoint c = unsafeFromInt (fromEnum c)
@@ -83,7 +72,6 @@ fromCodePoint c = unsafeFromInt (fromEnum c)
 -- https://en.wikipedia.org/wiki/Rabin%E2%80%93Karp_algorithm
 newtype RollingHash = RollingHash {
     base    :: Base
-  -- , modulus :: Modulus   -- in our case, the modulus is (top :: UInt64)
   , len     :: Int
   , basePowLen :: Base  -- pow base len % modulus (stored for performance reasons)
   }
@@ -101,16 +89,6 @@ mkRollingHash base len = RollingHash { base
     -- basePowLen = foldl (\acc _l -> (acc*base) `mod` modulus) (unsafeFromInt 1) (1..(len - 1))
     basePowLen = foldl (\acc _l -> (acc*base)) (unsafeFromInt 1) (1..(len - 1))
 
--- -- | NOTE: xs must be of length RollingHash.len
--- hashRH :: RollingHash -> Array Base -> Hash
--- hashRH rh@(RollingHash { base, modulus }) xs =
---   -- foldl (\acc x -> (((acc*base) `mod` modulus) + x) `mod` modulus) (unsafeFromInt 0) xs
---   foldl (\acc x -> rehashRH rh acc (unsafeFromInt 0) x) (unsafeFromInt 0) xs
-
--- rehashRH :: RollingHash -> Hash -> Base -> Base -> Hash
--- rehashRH (RollingHash { base, basePowLen, modulus }) h old new =
---   ((h + (modulus - old)*basePowLen)*base + new) `mod` modulus
-
 
 -- | NOTE: xs must be of length RollingHash.len
 hashU64 :: RollingHash -> Array Base -> Hash
@@ -161,23 +139,6 @@ hashStruct pats = { hash, hashMap, hLen, pats, rehash, rehashChar }
                          (mapWithIndex (\i a -> Tuple (hash a) [i]) pats)
 
 
-    -- hLen' = fromInt hLen
-    -- shDi = case 32 `quot` hLen of
-    --           q | q < 4 -> q
-    --             | otherwise -> 4
-    -- outS = fromInt (shDi * hLen)
-    
-    -- rehash :: UInt -> CodePoint -> CodePoint -> UInt
-    -- rehash = case shDi of
-    --             1 -> rehash' (fromInt 1) hLen'
-    --             2 -> rehash' (fromInt 2) outS
-    --             3 -> rehash' (fromInt 3) outS
-    --             _ -> rehash' (fromInt 4) outS
-    -- hash :: String -> UInt
-    -- hash = foldl (\h w -> (h `shl` fromInt shDi) + fromCodePoint w) (fromInt 0)
-    --     <<< S.toCodePointArray
-    --     <<< S.take hLen
-
 
 -- $overview
 --

test/Main.purs

@@ -9,5 +9,5 @@ import Test.Spec.Runner (runSpec)
 
 main :: Effect Unit
 main = launchAff_ do
-  specs <- discover "Data\\.String\\.Search\\..*Spec"
+  specs <- discover "Test\\.Data\\.String\\.Search\\..*Spec"
   runSpec [consoleReporter] specs

test/Data/String/Search/Spec.purs → test/Test/Data/String/Search/Spec.purs

-module Data.String.Search.KarpRabin.Spec where
+module Test.Data.String.Search.KarpRabin.Spec where
 
-import Prelude
 import Data.Array (index)
-import Data.Bounded (class Bounded)
-import Data.Bounded.Generic (genericTop, genericBottom)
-import Data.Enum (class BoundedEnum, class Enum)
-import Data.Enum.Generic (genericCardinality, genericToEnum, genericFromEnum, genericSucc, genericPred)
-import Data.Eq (class Eq)
-import Data.Eq.Generic (genericEq)
 import Data.Foldable (all)
-import Data.Generic.Rep (class Generic)
 import Data.Maybe (Maybe(..), isJust)
-import Data.Ord (class Ord)
-import Data.Ord.Generic (genericCompare)
-import Data.String (drop, stripPrefix, Pattern(..), codePointFromChar, CodePoint)
-import Data.String.Search.KarpRabin (indicesOfAny, mkRollingHash, hashU64, rehashU64, hashStruct, fromCodePoint)  -- indicesOfAnyLegacy,
+import Data.String (drop, stripPrefix, Pattern(..))
+import Data.String.Search.KarpRabin (indicesOfAny, mkRollingHash, hashU64, rehashU64, hashStruct, fromCodePoint)
 import Data.String.Search.Utils (slidingWindow)
 import Data.Tuple (Tuple(..))
-import Data.UInt64 (unsafeFromInt, UInt64)
+import Data.UInt64 (unsafeFromInt)
+import Prelude
+import Test.Data.String.Search.Utils (CodePointA(..))
 import Test.QuickCheck ((<?>))
-import Test.QuickCheck.Arbitrary
-import Test.QuickCheck.Gen (enum)
 import Test.Spec (Spec, describe, it)
 import Test.Spec.Assertions (shouldEqual)
 import Test.Spec.QuickCheck (quickCheck')
 
 
-fromInt = unsafeFromInt
-
-
-newtype CodePointA = CodePointA CodePoint
-
-derive instance Generic CodePointA _
-instance Eq CodePointA where
-  eq = genericEq
-instance Ord CodePointA where
-  compare = genericCompare
-instance Bounded CodePointA where
-  top = genericTop
-  bottom = genericBottom
-instance Enum CodePointA where
-  succ = genericSucc
-  pred = genericPred
-instance BoundedEnum CodePointA where
-  cardinality = genericCardinality
-  toEnum = genericToEnum
-  fromEnum = genericFromEnum
-instance Arbitrary CodePointA where
-  arbitrary = enum
-
 
 validIndices :: Array String -> String -> Boolean
 validIndices pats input = all validIndex (indicesOfAny pats input)
@@ -62,9 +29,6 @@ validIndices pats input = all validIndex (indicesOfAny pats input)
                         -- <?> (show input' <> " should start with " <> show pat)
             Nothing  -> false -- Failed "out of bounds pattern"
 
--- indicesOfAny :: Array String -> String -> Array (Tuple Int (Array Int))
--- indicesOfAny = indicesOfAnyLegacy
-
 spec :: Spec Unit
 spec =
   describe "KarpRabin" do
@@ -73,11 +37,11 @@ spec =
         [[1, 2], [2, 3], [3, 4]]
     
     it "rolling hash works 1" do
-      let rh = mkRollingHash (fromInt 7) 3
-      let a = fromInt 1
-      let b = fromInt 2
-      let c = fromInt 3
-      let d = fromInt 4
+      let rh = mkRollingHash (unsafeFromInt 7) 3
+      let a = unsafeFromInt 1
+      let b = unsafeFromInt 2
+      let c = unsafeFromInt 3
+      let d = unsafeFromInt 4
 
       let h1 = hashU64 rh [a, b, c]
           h2 = hashU64 rh [b, c, d]
@@ -87,7 +51,7 @@ spec =
       h3 `shouldEqual` rehashU64 rh h2 b a
 
     it "rolling hash works 2 (quickcheck)" $ do
-      let rh = mkRollingHash (fromInt 256) 3
+      let rh = mkRollingHash (unsafeFromInt 256) 3
 
       quickCheck' 2000 \(CodePointA a') (CodePointA b') (CodePointA c') (CodePointA d') ->
         let a = fromCodePoint a'

test/Test/Data/String/Utils.purs

+module Test.Data.String.Search.Utils where
+
+import Data.Bounded.Generic (genericTop, genericBottom)
+import Data.Enum (class BoundedEnum, class Enum)
+import Data.Enum.Generic (genericCardinality, genericToEnum, genericFromEnum, genericSucc, genericPred)
+import Data.Eq.Generic (genericEq)
+import Data.Generic.Rep (class Generic)
+import Data.String (CodePoint)
+import Prelude (class Bounded, class Eq, class Ord)
+import Data.Ord.Generic (genericCompare)
+import Test.QuickCheck.Arbitrary (class Arbitrary)
+import Test.QuickCheck.Gen (enum)
+
+
+newtype CodePointA = CodePointA CodePoint
+
+derive instance Generic CodePointA _
+instance Eq CodePointA where
+  eq = genericEq
+instance Ord CodePointA where
+  compare = genericCompare
+instance Bounded CodePointA where
+  top = genericTop
+  bottom = genericBottom
+instance Enum CodePointA where
+  succ = genericSucc
+  pred = genericPred
+instance BoundedEnum CodePointA where
+  cardinality = genericCardinality
+  toEnum = genericToEnum
+  fromEnum = genericFromEnum
+instance Arbitrary CodePointA where
+  arbitrary = enum
+