Initial commit and a working version of KarpRabin

.envrc

+use nix

.gitignore

+.spago/
+node_modules/
+output/

nix/pinned.nix

+import (
+  builtins.fetchTarball {
+    url = "https://github.com/NixOS/nixpkgs/archive/22.11.tar.gz";
+  }
+)

packages.dhall

+let upstream =
+      https://github.com/garganscript/package-sets/releases/download/v0.1.7/release.dhall
+        sha256:52886309e1f0158a85427f80c1e3d47ce747c5f14fcec671a81fe5c2c711a6db
+
+in  upstream

shell.nix

+{ pkgs ? import ./nix/pinned.nix {} }:
+let
+  default-shell = import (
+    pkgs.fetchFromGitHub {
+      owner = "garganscript";
+      repo = "package-sets";
+      rev = "master";
+      sha256 = "RYFsTna5cg7EjynLvkFg87zTLSMeZw7DNIgPu9iXokk=";
+    } + "/default-shell.nix");
+
+  build = pkgs.writeShellScriptBin "build" ''
+    #!/usr/bin/env bash
+    set -e
+
+    echo "Installing JS Dependencies"
+    yarn
+
+    echo "Compiling"
+
+    # 0.15
+    spago build
+    #spago bundle-module --main Main --to dist/bundle.js
+  '';
+
+  test-ps = pkgs.writeShellScriptBin "test-ps" ''
+    #!/usr/bin/env bash
+    set -e
+
+    echo "Compiling"
+    yarn
+    echo "Testing"
+    spago -x test.dhall test --main Test.Main
+  '';
+in
+pkgs.mkShell {
+  name = "purescript-string-search";
+
+  buildInputs = [
+    build
+    test-ps
+    default-shell.purs
+    default-shell.easy-ps.psc-package
+    default-shell.easy-ps.spago
+    default-shell.build
+    default-shell.pkgs.dhall-json
+    default-shell.pkgs.nodejs
+  ];
+}

spago.dhall

+{-
+Welcome to a Spago project!
+You can edit this file as you like.
+
+Need help? See the following resources:
+- Spago documentation: https://github.com/purescript/spago
+- Dhall language tour: https://docs.dhall-lang.org/tutorials/Language-Tour.html
+
+When creating a new Spago project, you can use
+`spago init --no-comments` or `spago init -C`
+to generate this file without the comments in this block.
+-}
+{ name = "string-search"
+, dependencies =
+  [ "arrays"
+  , "debug"
+  , "enums"
+  , "foldable-traversable"
+  , "integers"
+  , "lists"
+  , "maybe"
+  , "ordered-collections"
+  , "partial"
+  , "prelude"
+  , "strings"
+  , "tuples"
+  , "uint"
+  ]
+, packages = ./packages.dhall
+, sources = [ "src/**/*.purs" ]
+}

src/Data/String/Search.purs

+module Data.String.Search where

src/Data/String/Search/Utils.purs

+module Data.String.Search.Utils where
+
+import Data.Array
+import Prelude
+
+slidingWindow :: forall a. Array a -> Int -> Array (Array a)
+slidingWindow lst len =
+  let diff = length lst - len
+  in
+   if diff < 0 then []
+   else (\idx -> slice idx (idx + len) lst) <$> 0 .. diff

test.dhall

+let conf = ./spago.dhall
+
+in      conf
+    //  { sources = conf.sources # [ "test/**/*.purs" ]
+        , dependencies =
+              conf.dependencies
+            # [ "aff", "effect", "spec", "spec-discovery", "spec-quickcheck" ]
+        }

test/Data/String/Search/Spec.purs

+module Data.String.Search.KarpRabin.Spec where
+
+import Prelude
+import Data.Array (index)
+import Data.Foldable (all)
+import Data.Maybe (Maybe(..), isJust)
+import Data.String (drop, stripPrefix, Pattern(..))
+import Data.String.Search.KarpRabin (indicesOfAnyLegacy, indicesOfAny)
+import Data.Tuple (Tuple(..))
+import Test.Spec (Spec, describe, it)
+import Test.Spec.Assertions (shouldEqual)
+import Test.Spec.QuickCheck (quickCheck')
+
+validIndices :: Array String -> String -> Boolean
+validIndices pats input = all validIndex (indicesOfAny pats input)
+  where
+    validIndex (Tuple i ps) = all validPat ps
+      where
+        input' = drop i input
+        validPat p =
+          case index pats p of
+            Just pat -> isJust (stripPrefix (Pattern pat) 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
+    it "works on a single pattern matching two times" do
+      let pats   = ["ab"]
+      let input  = "abcbab"
+      let output = [Tuple 0 [0], Tuple 4 [0]]
+      indicesOfAny pats input `shouldEqual` output
+      -- hashes: 1650, 1667, 1682, 1665, 1650
+
+    it "works on a many unmatching patterns" do
+      let pats   = ["abd","e","bac","abcbabe"]
+      let input  = "abcbab"
+      let output = []
+      indicesOfAny pats input `shouldEqual` output
+
+    it "works on a simple case" do
+      let pats   = ["ab","cb","bc","bca"]
+      let input  = "abcbab"
+      let output = [Tuple 0 [0]
+                   ,Tuple 1 [2]
+                   ,Tuple 2 [1]
+                   ,Tuple 4 [0]
+                   ]
+      indicesOfAny pats input `shouldEqual` output
+
+    it "works with overlaps" do
+      let pats   = ["aba"]
+      let input  = "ababa"
+      let output = [Tuple 0 [0]
+                   ,Tuple 2 [0]
+                   ]
+      indicesOfAny pats input `shouldEqual` output
+
+    it "returns valid indices" do
+      validIndices ["a","ab","ba","abc","aba","abab","abcde"]
+                   "ababarbabacbbababcaccacabbababa"
+          `shouldEqual` true
+
+    it "returns valid indices 2000 random samples" do
+      quickCheck' 2000 validIndices

test/Main.purs

+module Test.Main where
+
+import Prelude
+import Effect (Effect)
+import Effect.Aff (launchAff_)
+import Test.Spec.Discovery (discover)
+import Test.Spec.Reporter.Console (consoleReporter)
+import Test.Spec.Runner (runSpec)
+
+main :: Effect Unit
+main = launchAff_ do
+  specs <- discover "Data\\.String\\.Search\\..*Spec"
+  runSpec [consoleReporter] specs

yarn.lock

+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+