antlr.v4.runtime.atn.ATNConfigObjectEqualityComparator source code

1 module antlr.v4.runtime.atn.ATNConfigObjectEqualityComparator;
2 
3 import antlr.v4.runtime.atn.ATNConfig;
4 import antlr.v4.runtime.misc.MurmurHash;
5 
6 /**
7  * TODO add class description
8  */
9 class ATNConfigObjectEqualityComparator
10 {
11 
12     /**
13      * The single instance of ATNConfigObjectEqualityComparator.
14      */
15     private static __gshared ATNConfigObjectEqualityComparator instance_;
16 
17     public static bool opEquals(Object a, Object b)
18     {
19         if (a is b) {
20             return true;
21         } else
22             if (a is null || b is null) {
23                 return false;
24             }
25         auto objA = cast(ATNConfig)a;
26         auto objB = cast(ATNConfig)b;
27         bool scEqual = false;
28         if (objA.semanticContext is objB.semanticContext)
29             scEqual = true;
30         else
31             if (objA.semanticContext is null || objB.semanticContext is null)
32                 return false;
33         return objA.state.stateNumber == objB.state.stateNumber
34             && objA.alt == objB.alt
35             && (objA.context is objB.context ||
36                 (objA.context !is null && objB.context !is null &&
37                  objA.context.opEquals(objB.context)))
38             && scEqual
39             && objA.isPrecedenceFilterSuppressed == objB.isPrecedenceFilterSuppressed;
40     }
41 
42     /**
43      * @uml
44      * @trusted
45      * @nothrow
46      */
47     public static size_t toHash(Object o) @trusted nothrow
48     {
49         if (cast(ATNConfig)o)
50             {
51                 auto obj = cast(ATNConfig)o;
52                 size_t hashCode = MurmurHash.initialize(7);
53                 hashCode = MurmurHash.update(hashCode, obj.state.stateNumber);
54                 hashCode = MurmurHash.update(hashCode, obj.alt);
55                 hashCode = MurmurHash.update(hashCode, obj.context);
56                 hashCode = MurmurHash.update(hashCode, obj.semanticContext);
57                 hashCode = MurmurHash.finish(hashCode, 4);
58                 return hashCode;
59             }
60         return false;
61     }
62 
63     /**
64      * Creates the single instance of ATNConfigObjectEqualityComparator.
65      */
66     private shared static this()
67     {
68         instance_ = new ATNConfigObjectEqualityComparator;
69     }
70 
71     /**
72      * Returns: A single instance of ATNConfigObjectEqualityComparator.
73      */
74     public static ATNConfigObjectEqualityComparator instance()
75     {
76         return instance_;
77     }
78 
79 }