Modul speiger.src.collections
Package speiger.src.collections.shorts.maps.impl.misc

Klasse Short2ShortArrayMap

java.lang.Object
java.util.AbstractMap<Short,Short>
speiger.src.collections.shorts.maps.abstracts.AbstractShort2ShortMap
speiger.src.collections.shorts.maps.impl.misc.Short2ShortArrayMap
Alle implementierten Schnittstellen:
Map<Short,Short>, ShortUnaryOperator, Short2ShortMap, Short2ShortOrderedMap
public class Short2ShortArrayMap extends AbstractShort2ShortMap implements Short2ShortOrderedMap
A Very Specific Type Specific implementation of a ArrayMap. This type of map is for very specific use cases that usaully would have lead to Tupled Lists otherwise. It also does not allow duplication (except for array constructors) and checks from last to first. It is not designed to be used as a HashMap replacement due to the poor performance it would cause.
Note:
in this implementation SubMaps do NOT keep track of parent changes fully. For performance reasons it will just have a start/end index and not values Anything within that range will be updated appropiatly a shrink/growth of elements will break SubMaps in some ways. This can be useful but be careful, this implementation does not shrink and only grows.

  • Konstruktordetails

    • Short2ShortArrayMap

      public Short2ShortArrayMap()
      Default Constructor

    • Short2ShortArrayMap

      public Short2ShortArrayMap(int minCapacity)
      Constructor that defines the minimum capacity
      Parameter:
      minCapacity - the minimum capacity the HashMap is allowed to be.
      Löst aus:
      IllegalStateException - if the minimum capacity is negative

    • Short2ShortArrayMap

      public Short2ShortArrayMap(Short[] keys, Short[] values)
      Helper constructor that allow to create a map from boxed values (it will unbox them)
      Parameter:
      keys - the keys that should be put into the map
      values - the values that should be put into the map.
      Löst aus:
      IllegalStateException - if the keys and values do not match in length

    • Short2ShortArrayMap

      public Short2ShortArrayMap(Short[] keys, Short[] values, int length)
      Helper constructor that allow to create a map from boxed values (it will unbox them) with a custom length
      Parameter:
      keys - the keys that should be put into the map
      values - the values that should be put into the map.
      length - the amount of values that should be pulled from the array
      Löst aus:
      IllegalStateException - if the keys and values do not match in length

    • Short2ShortArrayMap

      public Short2ShortArrayMap(short[] keys, short[] values)
      Helper constructor that allow to create a map from unboxed values
      Parameter:
      keys - the keys that should be put into the map
      values - the values that should be put into the map.
      Löst aus:
      IllegalStateException - if the keys and values do not match in lenght

    • Short2ShortArrayMap

      public Short2ShortArrayMap(short[] keys, short[] values, int length)
      Helper constructor that allow to create a map from unboxed values
      Parameter:
      keys - the keys that should be put into the map
      values - the values that should be put into the map.
      length - the amount of values that should be pulled from the array
      Löst aus:
      IllegalStateException - if the keys and values do not match in lenght

    • Short2ShortArrayMap

      public Short2ShortArrayMap(Map<? extends Short,? extends Short> map)
      A Helper constructor that allows to create a Map with exactly the same values as the provided map.
      Parameter:
      map - the values that should be present in the map

    • Short2ShortArrayMap

      public Short2ShortArrayMap(Short2ShortMap map)
      A Type Specific Helper function that allows to create a new Map with exactly the same values as the provided map.
      Parameter:
      map - the values that should be present in the map

  • Methodendetails

    • put

      public short put(short key, short value)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      Type Specific method to reduce boxing/unboxing of values
      Angegeben von:
      put in Schnittstelle Short2ShortMap
      Parameter:
      key - the key that should be inserted,
      value - the value that should be inserted
      Gibt zurück:
      the last present value or default return value.
      Siehe auch:

    • putIfAbsent

      public short putIfAbsent(short key, short value)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      Type Specific method to reduce boxing/unboxing of values
      Angegeben von:
      putIfAbsent in Schnittstelle Short2ShortMap
      Parameter:
      key - the key that should be inserted,
      value - the value that should be inserted
      Gibt zurück:
      the last present value or default return value.
      Siehe auch:

    • addTo

      public short addTo(short key, short value)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Helper method to add a primitives together. If key is not present then this functions as a put.
      Angegeben von:
      addTo in Schnittstelle Short2ShortMap
      Parameter:
      key - the key that should be inserted,
      value - the value that should be inserted / added
      Gibt zurück:
      the last present value or default return value.

    • subFrom

      public short subFrom(short key, short value)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Helper method to subtract from primitive from each other. If the key is not present it will just return the defaultValue How the implementation works is that it will subtract from the current value (if not present it will do nothing) and fence it to the Short2ShortMap.getDefaultReturnValue() If the fence is reached the element will be automaticall removed
      Angegeben von:
      subFrom in Schnittstelle Short2ShortMap
      Parameter:
      key - that should be subtract from
      value - that should be subtract
      Gibt zurück:
      the last present or default return value

    • putAndMoveToFirst

      public short putAndMoveToFirst(short key, short value)
      Beschreibung aus Schnittstelle kopiert: Short2ShortOrderedMap
      A customized put method that allows you to insert into the first index.
      Angegeben von:
      putAndMoveToFirst in Schnittstelle Short2ShortOrderedMap
      Parameter:
      key - the key that should be inserted
      value - the value that should be inserted
      Gibt zurück:
      the previous present or default return value
      Siehe auch:

    • putAndMoveToLast

      public short putAndMoveToLast(short key, short value)
      Beschreibung aus Schnittstelle kopiert: Short2ShortOrderedMap
      A customized put method that allows you to insert into the last index. (This may be nessesary depending on the implementation)
      Angegeben von:
      putAndMoveToLast in Schnittstelle Short2ShortOrderedMap
      Parameter:
      key - the key that should be inserted
      value - the value that should be inserted
      Gibt zurück:
      the previous present or default return value
      Siehe auch:

    • moveToFirst

      public boolean moveToFirst(short key)
      Beschreibung aus Schnittstelle kopiert: Short2ShortOrderedMap
      A specific move method to move a given key/value to the first index.
      Angegeben von:
      moveToFirst in Schnittstelle Short2ShortOrderedMap
      Parameter:
      key - that should be moved to the first index
      Gibt zurück:
      true if the value was moved.

    • moveToLast

      public boolean moveToLast(short key)
      Beschreibung aus Schnittstelle kopiert: Short2ShortOrderedMap
      A specific move method to move a given key/value to the last index.
      Angegeben von:
      moveToLast in Schnittstelle Short2ShortOrderedMap
      Parameter:
      key - that should be moved to the first last
      Gibt zurück:
      true if the value was moved.

    • containsKey

      public boolean containsKey(short key)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      Type Specific method to reduce boxing/unboxing of values
      Angegeben von:
      containsKey in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      containsKey in Klasse AbstractShort2ShortMap
      Parameter:
      key - element that is searched for
      Gibt zurück:
      if the key is present

    • containsValue

      public boolean containsValue(short value)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      Type Specific method to reduce boxing/unboxing of values
      Angegeben von:
      containsValue in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      containsValue in Klasse AbstractShort2ShortMap
      Parameter:
      value - element that is searched for
      Gibt zurück:
      if the value is present

    • containsKey

      public boolean containsKey(Object key)
      Angegeben von:
      containsKey in Schnittstelle Map<Short,Short>
      Angegeben von:
      containsKey in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      containsKey in Klasse AbstractMap<Short,Short>
      Parameter:
      key - that is searched for.
      Gibt zurück:
      true if found
      Siehe auch:

    • containsValue

      public boolean containsValue(Object value)
      Angegeben von:
      containsValue in Schnittstelle Map<Short,Short>
      Angegeben von:
      containsValue in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      containsValue in Klasse AbstractMap<Short,Short>
      Parameter:
      value - that is searched for.
      Gibt zurück:
      true if found
      Siehe auch:

    • get

      public short get(short key)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Type Specific get method to reduce boxing/unboxing
      Angegeben von:
      get in Schnittstelle Short2ShortMap
      Parameter:
      key - the key that is searched for
      Gibt zurück:
      the searched value or default return value

    • getOrDefault

      public short getOrDefault(short key, short defaultValue)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Type Specific getOrDefault method to reduce boxing/unboxing
      Angegeben von:
      getOrDefault in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      getOrDefault in Klasse AbstractShort2ShortMap
      Parameter:
      key - the key that is searched for
      defaultValue - the value that should be returned if the key is not present
      Gibt zurück:
      the searched value or defaultValue value

    • getAndMoveToFirst

      public short getAndMoveToFirst(short key)
      Beschreibung aus Schnittstelle kopiert: Short2ShortOrderedMap
      A Specific get method that allows to move teh given key/value int the first index.
      Angegeben von:
      getAndMoveToFirst in Schnittstelle Short2ShortOrderedMap
      Parameter:
      key - that is searched for
      Gibt zurück:
      the given value for the requested key or default return value

    • getAndMoveToLast

      public short getAndMoveToLast(short key)
      Beschreibung aus Schnittstelle kopiert: Short2ShortOrderedMap
      A Specific get method that allows to move teh given key/value int the last index.
      Angegeben von:
      getAndMoveToLast in Schnittstelle Short2ShortOrderedMap
      Parameter:
      key - that is searched for
      Gibt zurück:
      the given value for the requested key or default return value

    • firstShortKey

      public short firstShortKey()
      Beschreibung aus Schnittstelle kopiert: Short2ShortOrderedMap
      A method to get the first Key of a Map.
      Angegeben von:
      firstShortKey in Schnittstelle Short2ShortOrderedMap
      Gibt zurück:
      the first key in the map

    • lastShortKey

      public short lastShortKey()
      Beschreibung aus Schnittstelle kopiert: Short2ShortOrderedMap
      A method to get the last Key of a Map.
      Angegeben von:
      lastShortKey in Schnittstelle Short2ShortOrderedMap
      Gibt zurück:
      the last key in the map

    • firstShortValue

      public short firstShortValue()
      Beschreibung aus Schnittstelle kopiert: Short2ShortOrderedMap
      A method to get the first Value of a Map.
      Angegeben von:
      firstShortValue in Schnittstelle Short2ShortOrderedMap
      Gibt zurück:
      the first key in the map

    • lastShortValue

      public short lastShortValue()
      Beschreibung aus Schnittstelle kopiert: Short2ShortOrderedMap
      A method to get the last Value of a Map.
      Angegeben von:
      lastShortValue in Schnittstelle Short2ShortOrderedMap
      Gibt zurück:
      the last key in the map

    • pollFirstShortKey

      public short pollFirstShortKey()
      Beschreibung aus Schnittstelle kopiert: Short2ShortOrderedMap
      A method to get and remove the first Key of a Map.
      Angegeben von:
      pollFirstShortKey in Schnittstelle Short2ShortOrderedMap
      Gibt zurück:
      the first key in the map

    • pollLastShortKey

      public short pollLastShortKey()
      Beschreibung aus Schnittstelle kopiert: Short2ShortOrderedMap
      A method to get and remove the last Key of a Map.
      Angegeben von:
      pollLastShortKey in Schnittstelle Short2ShortOrderedMap
      Gibt zurück:
      the last key in the map

    • remove

      public short remove(short key)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      Type Specific remove function to reduce boxing/unboxing
      Angegeben von:
      remove in Schnittstelle Short2ShortMap
      Parameter:
      key - the element that should be removed
      Gibt zurück:
      the value that was removed or default return value

    • removeOrDefault

      public short removeOrDefault(short key, short defaultValue)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      Type-Specific Remove function with a default return value if wanted.
      Angegeben von:
      removeOrDefault in Schnittstelle Short2ShortMap
      Parameter:
      key - the element that should be removed
      defaultValue - the value that should be returned if the entry doesn't exist
      Gibt zurück:
      the value that was removed or default value
      Siehe auch:

    • remove

      public boolean remove(short key, short value)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      Type Specific remove function to reduce boxing/unboxing
      Angegeben von:
      remove in Schnittstelle Short2ShortMap
      Parameter:
      key - the element that should be removed
      value - the expected value that should be found
      Gibt zurück:
      true if the key and value was found and removed
      Siehe auch:

    • remove

      public Short remove(Object key)
      Angegeben von:
      remove in Schnittstelle Map<Short,Short>
      Angegeben von:
      remove in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      remove in Klasse AbstractShort2ShortMap
      Parameter:
      key - the element that should be removed
      Gibt zurück:
      the value that was removed or default return value
      Siehe auch:

    • remove

      public boolean remove(Object key, Object value)
      Angegeben von:
      remove in Schnittstelle Map<Short,Short>
      Angegeben von:
      remove in Schnittstelle Short2ShortMap
      Parameter:
      key - the element that should be removed
      value - the expected value that should be found
      Gibt zurück:
      true if the key and value was found and removed
      Siehe auch:

    • forEach

      public void forEach(ShortShortConsumer action)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      Type Specific forEach method to reduce boxing/unboxing
      Angegeben von:
      forEach in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      forEach in Klasse AbstractShort2ShortMap
      Parameter:
      action - processor of the values that are iterator over

    • keySet

      public ShortOrderedSet keySet()
      Angegeben von:
      keySet in Schnittstelle Map<Short,Short>
      Angegeben von:
      keySet in Schnittstelle Short2ShortMap
      Angegeben von:
      keySet in Schnittstelle Short2ShortOrderedMap
      Setzt außer Kraft:
      keySet in Klasse AbstractShort2ShortMap

    • values

      public ShortCollection values()
      Angegeben von:
      values in Schnittstelle Map<Short,Short>
      Angegeben von:
      values in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      values in Klasse AbstractShort2ShortMap

    • short2ShortEntrySet

      public ObjectOrderedSet<Short2ShortMap.Entry> short2ShortEntrySet()
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      Type Sensitive EntrySet to reduce boxing/unboxing and optionally Temp Object Allocation.
      Angegeben von:
      short2ShortEntrySet in Schnittstelle Short2ShortMap
      Angegeben von:
      short2ShortEntrySet in Schnittstelle Short2ShortOrderedMap
      Gibt zurück:
      a EntrySet of the collection

    • replace

      public boolean replace(short key, short oldValue, short newValue)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Type Specific replace method to replace an existing value
      Angegeben von:
      replace in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      replace in Klasse AbstractShort2ShortMap
      Parameter:
      key - the element that should be searched for
      oldValue - the expected value to be replaced
      newValue - the value to replace the oldValue with.
      Gibt zurück:
      true if the value got replaced

    • replace

      public short replace(short key, short value)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Type Specific replace method to reduce boxing/unboxing replace an existing value
      Angegeben von:
      replace in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      replace in Klasse AbstractShort2ShortMap
      Parameter:
      key - the element that should be searched for
      value - the value to replace with.
      Gibt zurück:
      the present value or default return value

    • computeShort

      public short computeShort(short key, ShortShortUnaryOperator mappingFunction)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Type Specific compute method to reduce boxing/unboxing If the generated value equals the getDefaultReturnValue it will simply not insert it since that is treated as "null". A "Null Value" will be treated as "Do not insert/remove" based on how the Java has specified it.
      Angegeben von:
      computeShort in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      computeShort in Klasse AbstractShort2ShortMap
      Parameter:
      key - the key that should be computed
      mappingFunction - the operator that should generate the value
      Gibt zurück:
      the result of the computation

    • computeShortIfAbsent

      public short computeShortIfAbsent(short key, ShortUnaryOperator mappingFunction)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Type Specific computeIfAbsent method to reduce boxing/unboxing If the generated value equals the getDefaultReturnValue it will simply not insert it since that is treated as "null". A "Null Value" will be treated as "Do not insert/remove" based on how the Java has specified it.
      Angegeben von:
      computeShortIfAbsent in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      computeShortIfAbsent in Klasse AbstractShort2ShortMap
      Parameter:
      key - the key that should be computed
      mappingFunction - the operator that should generate the value if not present
      Gibt zurück:
      the result of the computed value or present value

    • supplyShortIfAbsent

      public short supplyShortIfAbsent(short key, ShortSupplier valueProvider)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Supplier based computeIfAbsent function to fill the most used usecase of this function If the generated value equals the getDefaultReturnValue it will simply not insert it since that is treated as "null". A "Null Value" will be treated as "Do not insert/remove" based on how the Java has specified it.
      Angegeben von:
      supplyShortIfAbsent in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      supplyShortIfAbsent in Klasse AbstractShort2ShortMap
      Parameter:
      key - the key that should be computed
      valueProvider - the value if not present
      Gibt zurück:
      the result of the computed value or present value

    • computeShortIfPresent

      public short computeShortIfPresent(short key, ShortShortUnaryOperator mappingFunction)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Type Specific compute method to reduce boxing/unboxing If the generated value equals the getDefaultReturnValue it will simply not insert it since that is treated as "null". A "Null Value" will be treated as "Do not insert/remove" based on how the Java has specified it.
      Angegeben von:
      computeShortIfPresent in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      computeShortIfPresent in Klasse AbstractShort2ShortMap
      Parameter:
      key - the key that should be computed
      mappingFunction - the operator that should generate the value if present
      Gibt zurück:
      the result of the default return value or present value

    • computeShortNonDefault

      public short computeShortNonDefault(short key, ShortShortUnaryOperator mappingFunction)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Type Specific compute method to reduce boxing/unboxing If the generated value equals the getDefaultReturnValue it will simply not insert it since that is treated as "null". A "Null Value" will be treated as "Do not insert/remove" based on how the Java has specified it.
      Angegeben von:
      computeShortNonDefault in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      computeShortNonDefault in Klasse AbstractShort2ShortMap
      Parameter:
      key - the key that should be computed
      mappingFunction - the operator that should generate the value
      Gibt zurück:
      the result of the computation

    • computeShortIfAbsentNonDefault

      public short computeShortIfAbsentNonDefault(short key, ShortUnaryOperator mappingFunction)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Type Specific computeIfAbsent method to reduce boxing/unboxing If the generated value equals the getDefaultReturnValue it will simply not insert it since that is treated as "null". A "Null Value" will be treated as "Do not insert/remove" based on how the Java has specified it.
      Angegeben von:
      computeShortIfAbsentNonDefault in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      computeShortIfAbsentNonDefault in Klasse AbstractShort2ShortMap
      Parameter:
      key - the key that should be computed
      mappingFunction - the operator that should generate the value if not present
      Gibt zurück:
      the result of the computed value or present value

    • supplyShortIfAbsentNonDefault

      public short supplyShortIfAbsentNonDefault(short key, ShortSupplier valueProvider)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Supplier based computeIfAbsent function to fill the most used usecase of this function If the generated value equals the getDefaultReturnValue it will simply not insert it since that is treated as "null". A "Null Value" will be treated as "Do not insert/remove" based on how the Java has specified it.
      Angegeben von:
      supplyShortIfAbsentNonDefault in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      supplyShortIfAbsentNonDefault in Klasse AbstractShort2ShortMap
      Parameter:
      key - the key that should be computed
      valueProvider - the value if not present
      Gibt zurück:
      the result of the computed value or present value

    • computeShortIfPresentNonDefault

      public short computeShortIfPresentNonDefault(short key, ShortShortUnaryOperator mappingFunction)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Type Specific compute method to reduce boxing/unboxing If the generated value equals the getDefaultReturnValue it will simply not insert it since that is treated as "null". A "Null Value" will be treated as "Do not insert/remove" based on how the Java has specified it.
      Angegeben von:
      computeShortIfPresentNonDefault in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      computeShortIfPresentNonDefault in Klasse AbstractShort2ShortMap
      Parameter:
      key - the key that should be computed
      mappingFunction - the operator that should generate the value if present
      Gibt zurück:
      the result of the default return value or present value

    • mergeShort

      public short mergeShort(short key, short value, ShortShortUnaryOperator mappingFunction)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Type Specific merge method to reduce boxing/unboxing If the generated value equals the getDefaultReturnValue it will simply not insert it since that is treated as "null". A "Null Value" will be treated as "Do not insert/remove" based on how the Java has specified it.
      Angegeben von:
      mergeShort in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      mergeShort in Klasse AbstractShort2ShortMap
      Parameter:
      key - the key that should be be searched for
      value - the value that should be merged with
      mappingFunction - the operator that should generate the new Value
      Gibt zurück:
      the result of the merge

    • mergeAllShort

      public void mergeAllShort(Short2ShortMap m, ShortShortUnaryOperator mappingFunction)
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Bulk method for merging Maps. If the generated value equals the getDefaultReturnValue it will simply not insert it since that is treated as "null". A "Null Value" will be treated as "Do not insert/remove" based on how the Java has specified it.
      Angegeben von:
      mergeAllShort in Schnittstelle Short2ShortMap
      Setzt außer Kraft:
      mergeAllShort in Klasse AbstractShort2ShortMap
      Parameter:
      m - the entries that should be bulk added
      mappingFunction - the operator that should generate the new Value

    • size

      public int size()
      Angegeben von:
      size in Schnittstelle Map<Short,Short>
      Setzt außer Kraft:
      size in Klasse AbstractMap<Short,Short>

    • clear

      public void clear()
      Angegeben von:
      clear in Schnittstelle Map<Short,Short>
      Setzt außer Kraft:
      clear in Klasse AbstractMap<Short,Short>

    • copy

      public Short2ShortArrayMap copy()
      Beschreibung aus Schnittstelle kopiert: Short2ShortMap
      A Function that does a shallow clone of the Map itself. This function is more optimized then a copy constructor since the Map does not have to be unsorted/resorted. It can be compared to Cloneable but with less exception risk
      Angegeben von:
      copy in Schnittstelle Short2ShortMap
      Angegeben von:
      copy in Schnittstelle Short2ShortOrderedMap
      Setzt außer Kraft:
      copy in Klasse AbstractShort2ShortMap
      Gibt zurück:
      a Shallow Copy of the Map