From e6c8605573b2bb0121164dc1c718d0218804665a Mon Sep 17 00:00:00 2001
From: =?utf8?q?Sebastian=20Ho=C3=9F?= <seb@hoß.de>
Date: Tue, 29 Nov 2022 07:25:19 +0100
Subject: [PATCH] use ints as cache keys

---
 README.md                                          |  6 +-
 .../memoization/core/MemoizationDefaults.java      | 15 ++---
 .../memoization/core/MemoizationDefaultsTest.java  | 18 ++----
 .../java/wtf/metio/memoization/jdk/Memoize.java    | 38 ++++++-------
 .../metio/memoization/jool/Consumer0Memoizer.java  |  2 +-
 .../metio/memoization/jool/Consumer1Memoizer.java  |  2 +-
 .../wtf/metio/memoization/jool/MemoizeJool.java    | 64 +++++++++++-----------
 .../metio/memoization/lambda/MemoizeLambda.java    | 18 +++---
 .../wtf/metio/memoization/rxjava/MemoizeRx.java    | 36 ++++++------
 9 files changed, 91 insertions(+), 108 deletions(-)

diff --git a/README.md b/README.md
index bece58c..2bb2619 100644
--- a/README.md
+++ b/README.md
@@ -86,17 +86,17 @@ Function<INPUT, OUTPUT> memoizedFunction = Memoize.function(function, cache.asMa
 
 // memoize in Caffeine cache
 Supplier<OUTPUT> supplier                = ...;
-Cache<String, OUTPUT> cache              = ...; // com.github.benmanes.caffeine.cache.Cache
+Cache<Integer, OUTPUT> cache             = ...; // com.github.benmanes.caffeine.cache.Cache
 Supplier<OUTPUT> memoizedSupplier        = MemoizeRx.supplier(supplier, cache.asMap());
 
 // memoize in Guava cache
 Function3<T1, T2, T3, OUTPUT> function         = ...;
-Cache<String, OUTPUT> cache                    = ...; // com.google.common.cache.Cache
+Cache<Integer, OUTPUT> cache                   = ...; // com.google.common.cache.Cache
 Function3<T1, T2, T3, OUTPUT> memoizedFunction = MemoizeJool.function3(function, cache.asMap());
 
 // memoize in ConcurrentMap
 Fn4<T1, T2, T3, T4, OUTPUT> function         = ...;
-Map<String, OUTPUT> cache                    = ...;
+Map<Integer, OUTPUT> cache                   = ...;
 Fn4<T1, T2, T3, T4, OUTPUT> memoizedFunction = MemoizeLambda.fn4(function, cache);
 ```
 
diff --git a/memoization-core/src/main/java/wtf/metio/memoization/core/MemoizationDefaults.java b/memoization-core/src/main/java/wtf/metio/memoization/core/MemoizationDefaults.java
index 086a9b1..73575e3 100755
--- a/memoization-core/src/main/java/wtf/metio/memoization/core/MemoizationDefaults.java
+++ b/memoization-core/src/main/java/wtf/metio/memoization/core/MemoizationDefaults.java
@@ -5,9 +5,7 @@
 package wtf.metio.memoization.core;
 
 import java.util.Arrays;
-import java.util.Objects;
 import java.util.function.Supplier;
-import java.util.stream.Collectors;
 
 /**
  * Defaults used throughout the library.
@@ -23,8 +21,8 @@ public final class MemoizationDefaults {
      *
      * @return The default key supplier used throughout the library.
      */
-    public static Supplier<String> staticKey() {
-        return () -> "SUPPLIED";
+    public static Supplier<Integer> staticKey() {
+        return () -> 1;
     }
 
     /**
@@ -33,13 +31,8 @@ public final class MemoizationDefaults {
      * @param values The values to use.
      * @return The constructed cache key.
      */
-    public static String hashCodes(final Object... values) {
-//        return Arrays.hashCode(values);
-
-        return Arrays.stream(values)
-                .map(Object::hashCode)
-                .map(Objects::toString)
-                .collect(Collectors.joining(" "));
+    public static int hashCodes(final Object... values) {
+        return Arrays.hashCode(values);
     }
 
 }
diff --git a/memoization-core/src/test/java/wtf/metio/memoization/core/MemoizationDefaultsTest.java b/memoization-core/src/test/java/wtf/metio/memoization/core/MemoizationDefaultsTest.java
index 57c6f9a..be8107e 100755
--- a/memoization-core/src/test/java/wtf/metio/memoization/core/MemoizationDefaultsTest.java
+++ b/memoization-core/src/test/java/wtf/metio/memoization/core/MemoizationDefaultsTest.java
@@ -17,7 +17,7 @@ class MemoizationDefaultsTest {
     @Test
     void shouldDefineDefaultKeySupplier() {
         // given
-        Supplier<String> keySupplier;
+        Supplier<Integer> keySupplier;
 
         // when
         keySupplier = MemoizationDefaults.staticKey();
@@ -29,24 +29,14 @@ class MemoizationDefaultsTest {
     @Test
     void shouldDefineDefaultKey() {
         // given
-        final Supplier<String> keySupplier = MemoizationDefaults.staticKey();
+        final Supplier<Integer> keySupplier = MemoizationDefaults.staticKey();
 
         // when
-        final String defaultSuppliedKey = keySupplier.get();
+        final Integer defaultSuppliedKey = keySupplier.get();
 
         // then
         Assertions.assertNotNull(defaultSuppliedKey);
-        Assertions.assertEquals("SUPPLIED", defaultSuppliedKey);
-    }
-
-    @Test
-    void shouldConcatHashCodesWithWhitespaceInbetween() {
-        // given
-        // when
-        final String calculatedKey = MemoizationDefaults.hashCodes(1, 2);
-
-        // when
-        Assertions.assertEquals("1 2", calculatedKey);
+        Assertions.assertEquals(1, defaultSuppliedKey);
     }
 
     @Test
diff --git a/memoization-jdk/src/main/java/wtf/metio/memoization/jdk/Memoize.java b/memoization-jdk/src/main/java/wtf/metio/memoization/jdk/Memoize.java
index 69c3221..214bae2 100755
--- a/memoization-jdk/src/main/java/wtf/metio/memoization/jdk/Memoize.java
+++ b/memoization-jdk/src/main/java/wtf/metio/memoization/jdk/Memoize.java
@@ -132,7 +132,7 @@ public final class Memoize {
     @CheckReturnValue
     public static <OUTPUT> Callable<OUTPUT> callable(
             final Callable<OUTPUT> callable,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return callable(callable, staticKey(), cache);
     }
 
@@ -219,7 +219,7 @@ public final class Memoize {
     @CheckReturnValue
     public static Runnable runnable(
             final Runnable runnable,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return runnable(runnable, staticKey(), cache);
     }
 
@@ -332,7 +332,7 @@ public final class Memoize {
     @CheckReturnValue
     public static <FIRST, SECOND> BiConsumer<FIRST, SECOND> biConsumer(
             final BiConsumer<FIRST, SECOND> biConsumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return biConsumer(biConsumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -429,7 +429,7 @@ public final class Memoize {
     @CheckReturnValue
     public static <FIRST, SECOND, OUTPUT> BiFunction<FIRST, SECOND, OUTPUT> biFunction(
             final BiFunction<FIRST, SECOND, OUTPUT> biFunction,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return biFunction(biFunction, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -523,7 +523,7 @@ public final class Memoize {
     @CheckReturnValue
     public static <FIRST, SECOND> BiPredicate<FIRST, SECOND> biPredicate(
             final BiPredicate<FIRST, SECOND> predicate,
-            final Map<String, Boolean> cache) {
+            final Map<Integer, Boolean> cache) {
         return biPredicate(predicate, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -588,7 +588,7 @@ public final class Memoize {
     @CheckReturnValue
     public static BooleanSupplier booleanSupplier(
             final BooleanSupplier supplier,
-            final Map<String, Boolean> cache) {
+            final Map<Integer, Boolean> cache) {
         return booleanSupplier(supplier, staticKey(), cache);
     }
 
@@ -808,7 +808,7 @@ public final class Memoize {
     @CheckReturnValue
     public static DoubleBinaryOperator doubleBinaryOperator(
             final DoubleBinaryOperator operator,
-            final Map<String, Double> cache) {
+            final Map<Integer, Double> cache) {
         return doubleBinaryOperator(operator, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1106,7 +1106,7 @@ public final class Memoize {
     @CheckReturnValue
     public static DoubleSupplier doubleSupplier(
             final DoubleSupplier supplier,
-            final Map<String, Double> cache) {
+            final Map<Integer, Double> cache) {
         return doubleSupplier(supplier, staticKey(), cache);
     }
 
@@ -1585,7 +1585,7 @@ public final class Memoize {
     @CheckReturnValue
     public static IntBinaryOperator intBinaryOperator(
             final IntBinaryOperator operator,
-            final Map<String, Integer> cache) {
+            final Map<Integer, Integer> cache) {
         return intBinaryOperator(operator, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1883,7 +1883,7 @@ public final class Memoize {
     @CheckReturnValue
     public static IntSupplier intSupplier(
             final IntSupplier supplier,
-            final Map<String, Integer> cache) {
+            final Map<Integer, Integer> cache) {
         return intSupplier(supplier, staticKey(), cache);
     }
 
@@ -2269,7 +2269,7 @@ public final class Memoize {
     @CheckReturnValue
     public static LongBinaryOperator longBinaryOperator(
             final LongBinaryOperator operator,
-            final Map<String, Long> cache) {
+            final Map<Integer, Long> cache) {
         return longBinaryOperator(operator, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -2567,7 +2567,7 @@ public final class Memoize {
     @CheckReturnValue
     public static LongSupplier longSupplier(
             final LongSupplier supplier,
-            final Map<String, Long> cache) {
+            final Map<Integer, Long> cache) {
         return longSupplier(supplier, staticKey(), cache);
     }
 
@@ -2909,7 +2909,7 @@ public final class Memoize {
     @CheckReturnValue
     public static <INPUT> ObjDoubleConsumer<INPUT> objDoubleConsumer(
             final ObjDoubleConsumer<INPUT> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return objDoubleConsumer(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -2998,7 +2998,7 @@ public final class Memoize {
     @CheckReturnValue
     public static <INPUT> ObjIntConsumer<INPUT> objIntConsumer(
             final ObjIntConsumer<INPUT> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return objIntConsumer(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -3087,7 +3087,7 @@ public final class Memoize {
     @CheckReturnValue
     public static <INPUT> ObjLongConsumer<INPUT> objLongConsumer(
             final ObjLongConsumer<INPUT> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return objLongConsumer(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -3265,7 +3265,7 @@ public final class Memoize {
     @CheckReturnValue
     public static <OUTPUT> Supplier<OUTPUT> supplier(
             final Supplier<OUTPUT> supplier,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return supplier(supplier, staticKey(), asConcurrentMap(cache));
     }
 
@@ -3407,7 +3407,7 @@ public final class Memoize {
     @CheckReturnValue
     public static <FIRST, SECOND> ToDoubleBiFunction<FIRST, SECOND> toDoubleBiFunction(
             final ToDoubleBiFunction<FIRST, SECOND> function,
-            final Map<String, Double> cache) {
+            final Map<Integer, Double> cache) {
         return toDoubleBiFunction(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -3590,7 +3590,7 @@ public final class Memoize {
     @CheckReturnValue
     public static <FIRST, SECOND> ToIntBiFunction<FIRST, SECOND> toIntBiFunction(
             final ToIntBiFunction<FIRST, SECOND> function,
-            final Map<String, Integer> cache) {
+            final Map<Integer, Integer> cache) {
         return toIntBiFunction(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -3773,7 +3773,7 @@ public final class Memoize {
     @CheckReturnValue
     public static <FIRST, SECOND> ToLongBiFunction<FIRST, SECOND> toLongBiFunction(
             final ToLongBiFunction<FIRST, SECOND> function,
-            final Map<String, Long> cache) {
+            final Map<Integer, Long> cache) {
         return toLongBiFunction(function, MemoizationDefaults::hashCodes, cache);
     }
 
diff --git a/memoization-jool/src/main/java/wtf/metio/memoization/jool/Consumer0Memoizer.java b/memoization-jool/src/main/java/wtf/metio/memoization/jool/Consumer0Memoizer.java
index 3ff0635..7e93f9e 100644
--- a/memoization-jool/src/main/java/wtf/metio/memoization/jool/Consumer0Memoizer.java
+++ b/memoization-jool/src/main/java/wtf/metio/memoization/jool/Consumer0Memoizer.java
@@ -26,7 +26,7 @@ final class Consumer0Memoizer<KEY>
             final Consumer0 consumer) {
         super(cache);
         this.keySupplier = requireNonNull(keySupplier,
-                "Provide a key supplier, might just be 'MemoizationDefaults.defaultKeySupplier()'.");
+                "Provide a key supplier, might just be 'MemoizationDefaults.staticKey()'.");
         this.consumer = requireNonNull(consumer,
                 "Cannot memoize a NULL Consumer0 - provide an actual Consumer0 to fix this.");
     }
diff --git a/memoization-jool/src/main/java/wtf/metio/memoization/jool/Consumer1Memoizer.java b/memoization-jool/src/main/java/wtf/metio/memoization/jool/Consumer1Memoizer.java
index 217e3b3..a434050 100644
--- a/memoization-jool/src/main/java/wtf/metio/memoization/jool/Consumer1Memoizer.java
+++ b/memoization-jool/src/main/java/wtf/metio/memoization/jool/Consumer1Memoizer.java
@@ -26,7 +26,7 @@ final class Consumer1Memoizer<KEY, TYPE1>
             final Consumer1<TYPE1> consumer) {
         super(cache);
         this.keyFunction = requireNonNull(keyFunction,
-                "Provide a key function, might just be 'MemoizationDefaults.defaultKeySupplier()'.");
+                "Provide a key function, might just be 'MemoizationDefaults.staticKey()'.");
         this.consumer = requireNonNull(consumer,
                 "Cannot memoize a NULL Consumer1 - provide an actual Consumer1 to fix this.");
     }
diff --git a/memoization-jool/src/main/java/wtf/metio/memoization/jool/MemoizeJool.java b/memoization-jool/src/main/java/wtf/metio/memoization/jool/MemoizeJool.java
index fbcf52d..b611bef 100644
--- a/memoization-jool/src/main/java/wtf/metio/memoization/jool/MemoizeJool.java
+++ b/memoization-jool/src/main/java/wtf/metio/memoization/jool/MemoizeJool.java
@@ -130,7 +130,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static Consumer0 consumer0(
             final Consumer0 consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer0(consumer, staticKey(), cache);
     }
 
@@ -308,7 +308,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2> Consumer2<TYPE1, TYPE2> consumer2(
             final Consumer2<TYPE1, TYPE2> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer2(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -404,7 +404,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3> Consumer3<TYPE1, TYPE2, TYPE3> consumer3(
             final Consumer3<TYPE1, TYPE2, TYPE3> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer3(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -504,7 +504,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4> Consumer4<TYPE1, TYPE2, TYPE3, TYPE4> consumer4(
             final Consumer4<TYPE1, TYPE2, TYPE3, TYPE4> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer4(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -608,7 +608,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5> Consumer5<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5> consumer5(
             final Consumer5<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer5(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -716,7 +716,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6> Consumer6<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6> consumer6(
             final Consumer6<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer6(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -828,7 +828,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7> Consumer7<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7> consumer7(
             final Consumer7<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer7(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -944,7 +944,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8> Consumer8<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8> consumer8(
             final Consumer8<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer8(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1064,7 +1064,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9> Consumer9<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9> consumer9(
             final Consumer9<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer9(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1188,7 +1188,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10> Consumer10<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10> consumer10(
             final Consumer10<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer10(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1316,7 +1316,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11> Consumer11<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11> consumer11(
             final Consumer11<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer11(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1448,7 +1448,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12> Consumer12<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12> consumer12(
             final Consumer12<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer12(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1584,7 +1584,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13> Consumer13<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13> consumer13(
             final Consumer13<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer13(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1724,7 +1724,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14> Consumer14<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14> consumer14(
             final Consumer14<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer14(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1868,7 +1868,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, TYPE15> Consumer15<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, TYPE15> consumer15(
             final Consumer15<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, TYPE15> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer15(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -2016,7 +2016,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, TYPE15, TYPE16> Consumer16<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, TYPE15, TYPE16> consumer16(
             final Consumer16<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, TYPE15, TYPE16> consumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return consumer16(consumer, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -2135,7 +2135,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <OUTPUT> Function0<OUTPUT> function0(
             final Function0<OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function0(function, staticKey(), cache);
     }
 
@@ -2319,7 +2319,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, OUTPUT> Function2<TYPE1, TYPE2, OUTPUT> function2(
             final Function2<TYPE1, TYPE2, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function2(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -2419,7 +2419,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, OUTPUT> Function3<TYPE1, TYPE2, TYPE3, OUTPUT> function3(
             final Function3<TYPE1, TYPE2, TYPE3, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function3(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -2523,7 +2523,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, OUTPUT> Function4<TYPE1, TYPE2, TYPE3, TYPE4, OUTPUT> function4(
             final Function4<TYPE1, TYPE2, TYPE3, TYPE4, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function4(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -2631,7 +2631,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, OUTPUT> Function5<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, OUTPUT> function5(
             final Function5<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function5(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -2743,7 +2743,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, OUTPUT> Function6<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, OUTPUT> function6(
             final Function6<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function6(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -2859,7 +2859,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, OUTPUT> Function7<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, OUTPUT> function7(
             final Function7<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function7(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -2979,7 +2979,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, OUTPUT> Function8<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, OUTPUT> function8(
             final Function8<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function8(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -3103,7 +3103,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, OUTPUT> Function9<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, OUTPUT> function9(
             final Function9<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function9(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -3231,7 +3231,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, OUTPUT> Function10<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, OUTPUT> function10(
             final Function10<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function10(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -3363,7 +3363,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, OUTPUT> Function11<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, OUTPUT> function11(
             final Function11<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function11(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -3499,7 +3499,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, OUTPUT> Function12<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, OUTPUT> function12(
             final Function12<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function12(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -3639,7 +3639,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, OUTPUT> Function13<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, OUTPUT> function13(
             final Function13<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function13(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -3783,7 +3783,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, OUTPUT> Function14<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, OUTPUT> function14(
             final Function14<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function14(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -3931,7 +3931,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, TYPE15, OUTPUT> Function15<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, TYPE15, OUTPUT> function15(
             final Function15<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, TYPE15, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function15(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -4083,7 +4083,7 @@ public final class MemoizeJool {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, TYPE15, TYPE16, OUTPUT> Function16<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, TYPE15, TYPE16, OUTPUT> function16(
             final Function16<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, TYPE10, TYPE11, TYPE12, TYPE13, TYPE14, TYPE15, TYPE16, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function16(function, MemoizationDefaults::hashCodes, cache);
     }
 
diff --git a/memoization-lambda/src/main/java/wtf/metio/memoization/lambda/MemoizeLambda.java b/memoization-lambda/src/main/java/wtf/metio/memoization/lambda/MemoizeLambda.java
index fce222e..c1b123d 100644
--- a/memoization-lambda/src/main/java/wtf/metio/memoization/lambda/MemoizeLambda.java
+++ b/memoization-lambda/src/main/java/wtf/metio/memoization/lambda/MemoizeLambda.java
@@ -98,7 +98,7 @@ public final class MemoizeLambda {
     @CheckReturnValue
     public static <OUTPUT> Fn0<OUTPUT> fn0(
             final Fn0<OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return fn0(function, staticKey(), cache);
     }
 
@@ -189,7 +189,7 @@ public final class MemoizeLambda {
     @CheckReturnValue
     public static <INPUT, OUTPUT> Fn1<INPUT, OUTPUT> fn1(
             final Fn1<INPUT, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return fn1(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -284,7 +284,7 @@ public final class MemoizeLambda {
     @CheckReturnValue
     public static <TYPE1, TYPE2, OUTPUT> Fn2<TYPE1, TYPE2, OUTPUT> fn2(
             final Fn2<TYPE1, TYPE2, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return fn2(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -383,7 +383,7 @@ public final class MemoizeLambda {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, OUTPUT> Fn3<TYPE1, TYPE2, TYPE3, OUTPUT> fn3(
             final Fn3<TYPE1, TYPE2, TYPE3, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return fn3(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -487,7 +487,7 @@ public final class MemoizeLambda {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, OUTPUT> Fn4<TYPE1, TYPE2, TYPE3, TYPE4, OUTPUT> fn4(
             final Fn4<TYPE1, TYPE2, TYPE3, TYPE4, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return fn4(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -595,7 +595,7 @@ public final class MemoizeLambda {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, OUTPUT> Fn5<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, OUTPUT> fn5(
             final Fn5<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return fn5(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -707,7 +707,7 @@ public final class MemoizeLambda {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, OUTPUT> Fn6<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, OUTPUT> fn6(
             final Fn6<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return fn6(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -823,7 +823,7 @@ public final class MemoizeLambda {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, OUTPUT> Fn7<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, OUTPUT> fn7(
             final Fn7<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return fn7(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -943,7 +943,7 @@ public final class MemoizeLambda {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, OUTPUT> Fn8<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, OUTPUT> fn8(
             final Fn8<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return fn8(function, MemoizationDefaults::hashCodes, cache);
     }
 
diff --git a/memoization-rxjava/src/main/java/wtf/metio/memoization/rxjava/MemoizeRx.java b/memoization-rxjava/src/main/java/wtf/metio/memoization/rxjava/MemoizeRx.java
index 5b99f9d..520fe46 100644
--- a/memoization-rxjava/src/main/java/wtf/metio/memoization/rxjava/MemoizeRx.java
+++ b/memoization-rxjava/src/main/java/wtf/metio/memoization/rxjava/MemoizeRx.java
@@ -106,8 +106,8 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static Action action(
             final Action action,
-            final Map<String, String> cache) {
-        return action(action, () -> "SUPPLIED", cache);
+            final Map<Integer, Integer> cache) {
+        return action(action, () -> 1, cache);
     }
 
     /**
@@ -191,8 +191,8 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static Cancellable cancellable(
             final Cancellable cancellable,
-            final Map<String, String> cache) {
-        return cancellable(cancellable, () -> "SUPPLIED", cache);
+            final Map<Integer, Integer> cache) {
+        return cancellable(cancellable, () -> 1, cache);
     }
 
     /**
@@ -361,8 +361,8 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static BooleanSupplier booleanSupplier(
             final BooleanSupplier supplier,
-            final Map<String, Boolean> cache) {
-        return booleanSupplier(supplier, () -> "SUPPLIED", cache);
+            final Map<Integer, Boolean> cache) {
+        return booleanSupplier(supplier, () -> 1, cache);
     }
 
     /**
@@ -548,7 +548,7 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, OUTPUT> Function3<TYPE1, TYPE2, TYPE3, OUTPUT> function3(
             final Function3<TYPE1, TYPE2, TYPE3, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function3(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -652,7 +652,7 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, OUTPUT> Function4<TYPE1, TYPE2, TYPE3, TYPE4, OUTPUT> function4(
             final Function4<TYPE1, TYPE2, TYPE3, TYPE4, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function4(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -760,7 +760,7 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, OUTPUT> Function5<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, OUTPUT> function5(
             final Function5<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function5(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -872,7 +872,7 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, OUTPUT> Function6<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, OUTPUT> function6(
             final Function6<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function6(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -988,7 +988,7 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, OUTPUT> Function7<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, OUTPUT> function7(
             final Function7<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function7(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1108,7 +1108,7 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, OUTPUT> Function8<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, OUTPUT> function8(
             final Function8<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function8(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1232,7 +1232,7 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static <TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, OUTPUT> Function9<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, OUTPUT> function9(
             final Function9<TYPE1, TYPE2, TYPE3, TYPE4, TYPE5, TYPE6, TYPE7, TYPE8, TYPE9, OUTPUT> function,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return function9(function, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1517,8 +1517,8 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static <OUTPUT> Supplier<OUTPUT> supplier(
             final Supplier<OUTPUT> supplier,
-            final Map<String, OUTPUT> cache) {
-        return supplier(supplier, () -> "SUPPLIED", asConcurrentMap(cache));
+            final Map<Integer, OUTPUT> cache) {
+        return supplier(supplier, () -> 1, asConcurrentMap(cache));
     }
 
     /**
@@ -1721,7 +1721,7 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static <FIRST, SECOND> BiPredicate<FIRST, SECOND> biPredicate(
             final BiPredicate<FIRST, SECOND> predicate,
-            final Map<String, Boolean> cache) {
+            final Map<Integer, Boolean> cache) {
         return biPredicate(predicate, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1818,7 +1818,7 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static <FIRST, SECOND, OUTPUT> BiFunction<FIRST, SECOND, OUTPUT> biFunction(
             final BiFunction<FIRST, SECOND, OUTPUT> biFunction,
-            final Map<String, OUTPUT> cache) {
+            final Map<Integer, OUTPUT> cache) {
         return biFunction(biFunction, MemoizationDefaults::hashCodes, cache);
     }
 
@@ -1912,7 +1912,7 @@ public final class MemoizeRx {
     @CheckReturnValue
     public static <FIRST, SECOND> BiConsumer<FIRST, SECOND> biConsumer(
             final BiConsumer<FIRST, SECOND> biConsumer,
-            final Map<String, String> cache) {
+            final Map<Integer, Integer> cache) {
         return biConsumer(biConsumer, MemoizationDefaults::hashCodes, cache);
     }
 
-- 
2.11.4.GIT