added utility class and 'allMaps' function

haskell-experiments/haskell-experiments.cabal

@@ -81,6 +81,7 @@ test-suite haskell-exps-test
     Test.Datalog.DatalogParserSpec
     Test.Datalog.InMemoryDBSpec
     Test.Datalog.NaiveQESpec
+    Test.Utility.UtilitySpec
 
 library langfeatures
   import: warnings, commonSettings
@@ -95,6 +96,7 @@ library langfeatures
     Datalog.DatalogDB
     Datalog.NaiveQE
     Datalog.QueryEngine
+    Utility.Utility
 
 executable haskell-experiments
   import: warnings, commonSettings

haskell-experiments/src/Utility/Utility.hs

@@ -0,0 +1,22 @@
+{-# HLINT ignore "Redundant flip" #-}
+{-# LANGUAGE ImportQualifiedPost #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# OPTIONS_GHC -Wno-unrecognised-pragmas #-}
+{-# LANGUAGE DatatypeContexts #-}
+
+module Utility.Utility where
+
+import Control.Exception.Base
+import Data.List
+import Data.Maybe
+import Data.Set qualified as Set
+import Data.Text (Text)
+import Datalog.DatalogParser (Head (HeadSingle), Literal (..), Statement (..), Term (..), parseDatalog)
+import Datalog.DatalogDB
+
+import qualified Data.Map as Map
+
+-- All functions from domain to codomain
+allMaps :: Ord a => [a] -> [b] -> [Map.Map a b]
+allMaps []     _   = [Map.empty]
+allMaps (x:xs) cod = [ Map.insert x y m | y <- cod, m <- allMaps xs cod ]

haskell-experiments/test/Main.hs

@@ -7,6 +7,7 @@ import qualified Test.ArithmeticParserSpec as ArithmeticParserSpec
 import qualified Test.Datalog.DatalogParserSpec as DatalogParserSpec
 import qualified Test.Datalog.InMemoryDBSpec as InMemoryDBSpec
 import qualified Test.Datalog.NaiveQESpec as NaiveQESpec
+import qualified Test.Utility.UtilitySpec as UtilitySpec
 
 main :: IO ()
 main = hspec $ do
@@ -16,4 +17,4 @@ main = hspec $ do
     describe "DatalogParser" DatalogParserSpec.spec
     describe "InMemoryDB" InMemoryDBSpec.spec
     describe "NaiveQE" NaiveQESpec.spec
-
+    describe "Utility" UtilitySpec.spec

haskell-experiments/test/Test/Utility/UtilitySpec.hs

@@ -0,0 +1,31 @@
+{-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE DuplicateRecordFields #-}
+{-# LANGUAGE ImportQualifiedPost #-}
+{-# LANGUAGE OverloadedRecordDot #-}
+{-# HLINT ignore "Use const" #-}
+{-# HLINT ignore "Unused LANGUAGE pragma" #-}
+{-# HLINT ignore "Avoid lambda" #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeApplications #-}
+{-# LANGUAGE NoFieldSelectors #-}
+{-# LANGUAGE NoMonomorphismRestriction #-}
+{-# OPTIONS_GHC -Wno-unrecognised-pragmas #-}
+
+module Test.Utility.UtilitySpec where
+
+import Test.Hspec
+import Utility.Utility
+import qualified Data.Map as Map
+import Data.Map
+
+spec :: Spec
+spec = do
+  describe "UtilitySpec" do
+    it "..." $ do
+      uncharacteristic <$> (allMaps [1, 2, 3] [True, False]) `shouldMatchList` [
+        [1,2,3], [1,2], [1,3], [1], [2, 3], [2], [3], []
+        ]
+
+uncharacteristic :: forall a . Map a Bool -> [a]
+uncharacteristic intmap = [ x | (x, v) <- toList intmap, v ]
+