1 files changed, 110 insertions, 0 deletions
diff --git a/dotnet/Mammoth/Couscous/mammoth/internal/util/Maps.cs b/dotnet/Mammoth/Couscous/mammoth/internal/util/Maps.cs
new file mode 100644
index 0000000..bee2dac
--- /dev/null
+++ b/dotnet/Mammoth/Couscous/mammoth/internal/util/Maps.cs
@@ -0,0 +1,110 @@
+using System.Linq;
+using Mammoth.Couscous.java.util;
+using Mammoth.Couscous.java.lang;
+using Mammoth.Couscous.java.util.function;
+using Mammoth.Couscous;
+
+namespace Mammoth.Couscous.org.zwobble.mammoth.@internal.util
+{
+    internal static class Maps
+    {
+        internal static Map<K, V> map<K, V>() {
+            return ToJava.DictionaryToMap(new System.Collections.Generic.Dictionary<K, V>());
+        }
+        
+        internal static Map<K, V> map<K, V>(K key1, V value1) {
+            return ToJava.DictionaryToMap(new System.Collections.Generic.Dictionary<K, V> {
+                {key1, value1}
+            });
+        }
+        
+        internal static Map<K, V> map<K, V>(K key1, V value1, K key2, V value2) {
+            return ToJava.DictionaryToMap(new System.Collections.Generic.Dictionary<K, V> {
+                {key1, value1},
+                {key2, value2}
+            });
+        }
+        
+        internal static Map<K, V> toMap<T, K, V>(Iterable<T> iterable, Function<T, Map__Entry<K, V>> function) {
+            var dictionary = FromJava.IterableToEnumerable(iterable)
+                .Select(function.apply)
+                .ToDictionary(entry => entry.getKey(), entry => entry.getValue());
+            return ToJava.DictionaryToMap(dictionary);
+            
+        }
+        
+        internal static Map<K, T> toMapWithKey<T, K>(Iterable<T> iterable, Function<T, K> function) {
+            var dictionary = FromJava.IterableToEnumerable(iterable)
+                .ToDictionary(function.apply);
+            return ToJava.DictionaryToMap(dictionary);
+        }
+        
+        internal static Map<K, java.util.List<T>> toMultiMapWithKey<T, K>(Iterable<T> iterable, Function<T, K> function) {
+            var dictionary = FromJava.IterableToEnumerable(iterable)
+                .GroupBy(value => function.apply(value))
+                .ToDictionary(
+                    grouping => grouping.Key,
+                    grouping => ToJava.ListToList(grouping.ToList()));
+            return ToJava.DictionaryToMap(dictionary);
+        }
+        
+        internal static Optional<V> lookup<K, V>(Map<K, V> map, K key) {
+            return map._lookup(key);
+        }
+        
+        internal static Map<K2, V> eagerMapKeys<K1, K2, V>(Map<K1, V> map, Function<K1, K2> function) {
+            var dictionary = FromJava.MapToDictionary(map)
+                .ToDictionary(
+                    entry => function.apply(entry.Key),
+                    entry => entry.Value);
+            return ToJava.DictionaryToMap(dictionary);
+        }
+        
+        internal static Map<K, V2> eagerMapValues<K, V1, V2>(Map<K, V1> map, Function<V1, V2> function) {
+            var dictionary = FromJava.MapToDictionary(map)
+                .ToDictionary(
+                    entry => entry.Key,
+                    entry => function.apply(entry.Value));
+            return ToJava.DictionaryToMap(dictionary);
+        }
+        
+        internal static Map__Entry<K, V> entry<K, V>(K key, V value) {
+            return new Entry<K, V>(key, value);
+        }
+        
+        private class Entry<K, V> : Map__Entry<K, V> {
+            private readonly K _key;
+            private readonly V _value;
+            
+            internal Entry(K key, V value) {
+                this._key = key;
+                this._value = value;
+            }
+            
+            public K getKey() {
+                return _key;
+            }
+            
+            public V getValue() {
+                return _value;
+            }
+        }
+        
+        internal static Builder<K, V> builder<K, V>() {
+            return new Builder<K, V>();
+        }
+        
+        internal class Builder<K, V> {
+            private readonly System.Collections.Generic.IDictionary<K, V> _values = new System.Collections.Generic.Dictionary<K, V>();
+            
+            internal Builder<K, V> put(K key, V value) {
+                _values[key] = value;
+                return this;
+            }
+            
+            internal Map<K, V> build() {
+                return ToJava.DictionaryToMap(_values);
+            }
+        }
+    }
+}