Remove use of Google collections in Notes

1 files changed, 27 insertions, 3 deletions

diff --git a/src/main/java/org/zwobble/mammoth/internal/util/MammothMaps.java b/src/main/java/org/zwobble/mammoth/internal/util/MammothMaps.java
index 19fbfc4..873f90c 100644
--- a/src/main/java/org/zwobble/mammoth/internal/util/MammothMaps.java
+++ b/src/main/java/org/zwobble/mammoth/internal/util/MammothMaps.java
@@ -2,9 +2,7 @@ package org.zwobble.mammoth.internal.util;
 
 import com.google.common.collect.ImmutableMap;
 
-import java.util.AbstractMap;
-import java.util.Map;
-import java.util.Optional;
+import java.util.*;
 import java.util.function.Function;
 
 public class MammothMaps {
@@ -32,6 +30,10 @@ public class MammothMaps {
         return Optional.ofNullable(map.get(key));
     }
 
+    public static <T, K> Map<K, T> toMapWithKey(Iterable<T> iterable, Function<T, K> function) {
+        return toMap(iterable, element -> entry(function.apply(element), element));
+    }
+
     public static <T, K, V> Map<K, V> toMap(Iterable<T> iterable, Function<T, Map.Entry<K, V>> function) {
         ImmutableMap.Builder<K, V> builder = ImmutableMap.builder();
         for (T element : iterable) {
@@ -39,4 +41,26 @@ public class MammothMaps {
         }
         return builder.build();
     }
+
+    public static <T, K> Map<K, List<T>> toMultiMapWithKey(Iterable<T> iterable, Function<T, K> function) {
+        return toMultiMap(iterable, element -> entry(function.apply(element), element));
+    }
+
+    public static <T, K, V> Map<K, List<V>> toMultiMap(Iterable<T> iterable, Function<T, Map.Entry<K, V>> function) {
+        Map<K, List<V>> map = new HashMap<>();
+        for (T element : iterable) {
+            Map.Entry<K, V> pair = function.apply(element);
+            map.computeIfAbsent(pair.getKey(), key -> new ArrayList<V>())
+                .add(pair.getValue());
+        }
+        return map;
+    }
+
+    public static <K, V1, V2> Map<K, V2> eagerMapValues(Map<K, V1> map, Function<V1, V2> function) {
+        Map<K, V2> result = new HashMap<>();
+        for (Map.Entry<K, V1> element : map.entrySet()) {
+            result.put(element.getKey(), function.apply(element.getValue()));
+        }
+        return result;
+    }
 }