1 //
2 // DoubleImmutableMap.cs
3 //
4 // Authors:
5 // 	Alexander Chebaturkin (chebaturkin@gmail.com)
6 //
7 // Copyright (C) 2011 Alexander Chebaturkin
8 //
9 // Permission is hereby granted, free of charge, to any person obtaining
10 // a copy of this software and associated documentation files (the
11 // "Software"), to deal in the Software without restriction, including
12 // without limitation the rights to use, copy, modify, merge, publish,
13 // distribute, sublicense, and/or sell copies of the Software, and to
14 // permit persons to whom the Software is furnished to do so, subject to
15 // the following conditions:
16 //
17 // The above copyright notice and this permission notice shall be
18 // included in all copies or substantial portions of the Software.
19 //
20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
27 //
28 
29 using System;
30 using System.Collections.Generic;
31 
32 namespace Mono.CodeContracts.Static.DataStructures {
33 	class DoubleImmutableMap<A, B, C>
34 		where A : IEquatable<A>
35 		where B : IEquatable<B> {
36 		private readonly B[] EmptyCache = new B[0];
37 		private readonly IImmutableMap<A, IImmutableMap<B, C>> map;
38 
DoubleImmutableMap(IImmutableMap<A, IImmutableMap<B, C>> map)39 		private DoubleImmutableMap (IImmutableMap<A, IImmutableMap<B, C>> map)
40 		{
41 			this.map = map;
42 		}
43 
44 		public C this [A key1, B key2]
45 		{
46 			get
47 			{
48 				IImmutableMap<B, C> inner = this.map [key1];
49 				if (inner == null)
50 					return default(C);
51 				return inner [key2];
52 			}
53 		}
54 
55 		public int Keys1Count
56 		{
57 			get { return this.map.Count; }
58 		}
59 
60 		public IEnumerable<A> Keys1
61 		{
62 			get { return this.map.Keys; }
63 		}
64 
Add(A key1, B key2, C value)65 		public DoubleImmutableMap<A, B, C> Add (A key1, B key2, C value)
66 		{
67 			IImmutableMap<B, C> immutableMap = this.map [key1] ?? ImmutableMap<B, C>.Empty;
68 			return new DoubleImmutableMap<A, B, C> (this.map.Add (key1, immutableMap.Add (key2, value)));
69 		}
70 
RemoveAll(A key1)71 		public DoubleImmutableMap<A, B, C> RemoveAll (A key1)
72 		{
73 			return new DoubleImmutableMap<A, B, C> (this.map.Remove (key1));
74 		}
75 
Remove(A key1, B key2)76 		public DoubleImmutableMap<A, B, C> Remove (A key1, B key2)
77 		{
78 			IImmutableMap<B, C> inner = this.map [key1];
79 			if (inner == null)
80 				return this;
81 			IImmutableMap<B, C> newInner = inner.Remove (key2);
82 			if (newInner == inner)
83 				return this;
84 			return new DoubleImmutableMap<A, B, C> (this.map.Add (key1, newInner));
85 		}
86 
Empty(Func<A, int> uniqueIdGenerator)87 		public static DoubleImmutableMap<A, B, C> Empty (Func<A, int> uniqueIdGenerator)
88 		{
89 			return new DoubleImmutableMap<A, B, C> (ImmutableIntKeyMap<A, IImmutableMap<B, C>>.Empty (uniqueIdGenerator));
90 		}
91 
Contains(A key1, B key2)92 		public bool Contains (A key1, B key2)
93 		{
94 			IImmutableMap<B, C> inner = this.map [key1];
95 			if (inner == null)
96 				return false;
97 			return inner.ContainsKey (key2);
98 		}
99 
ContainsKey1(A key1)100 		public bool ContainsKey1 (A key1)
101 		{
102 			return this.map.ContainsKey (key1);
103 		}
104 
Keys2Count(A key1)105 		public int Keys2Count (A key1)
106 		{
107 			if (key1 == null)
108 				return 0;
109 			IImmutableMap<B, C> inner = this.map [key1];
110 			if (inner == null)
111 				return 0;
112 			return inner.Count;
113 		}
114 
Keys2(A key1)115 		public IEnumerable<B> Keys2 (A key1)
116 		{
117 			if (key1 == null)
118 				return this.EmptyCache;
119 
120 			IImmutableMap<B, C> inner = this.map [key1];
121 			if (inner == null)
122 				return this.EmptyCache;
123 			return inner.Keys;
124 		}
125 	}
126 }
127