/// <summary>
/// Retrieve a value from the map by key and pattern match the
/// result.
/// </summary>
/// <param name="key">Key to find</param>
/// <returns>Found value</returns>
public R Find <R>(K key, Func <V, R> Some, Func <R> None) =>
key == null
? None()
: match(MapModule.TryFind(Root, key, Comparer <K> .Default), Some, None);
/// <summary>
/// Retrieve a value from the map by key
/// </summary>
/// <param name="key">Key to find</param>
/// <returns>Found value</returns>
public Option <V> Find(K key) =>
key == null
? None
: MapModule.TryFind(Root, key, Comparer <K> .Default);
public bool Contains(KeyValuePair <K, V> pair) =>
match(MapModule.TryFind(Root, pair.Key, Comparer <K> .Default),
Some: v => ReferenceEquals(v, pair.Value),
None: () => false);
public Map <K, V> AddOrUpdate(K key, Func <V, V> Some, Func <V> None) =>
isnull(key)
? this
: match(MapModule.TryFind(Root, key, Comparer <K> .Default),
Some: x => SetItem(key, Some(x)),
None: () => Add(key, None()));
public Map <K, V> TrySetItem(K key, Func <V, V> Some, Func <Map <K, V>, Map <K, V> > None) =>
isnull(key)
? this
: match(MapModule.TryFind(Root, key, Comparer <K> .Default),
Some: x => SetItem(key, Some(x)),
None: () => None(this));
public Map <K, V> SetItem(K key, Func <V, V> Some) =>
isnull(key)
? this
: match(MapModule.TryFind(Root, key, Comparer <K> .Default),
Some: x => SetItem(key, Some(x)),
None: () => raise <Map <K, V> >(new ArgumentException("Key not found in Map")));