1 using System;
 2 using System.Json;
 3 
 4 Result<UniquePtr<JsonArray>> MakePhilosophers()
 5 {
 6     JsonArray* philosophers = new JsonArray();
 7     JsonObject* aristotle = new JsonObject();
 8     auto result = aristotle->AddField("name", new JsonString(u"Aristotles"));
 9     if (result.Error()) return Result<UniquePtr<JsonArray>>(ErrorId(result.GetErrorId()));
10     philosophers->AddItem(aristotle);
11 
12     JsonObject* plato = new JsonObject();
13     result = plato->AddField("name", new JsonString(u"Plato"));
14     if (result.Error()) return Result<UniquePtr<JsonArray>>(ErrorId(result.GetErrorId()));
15     philosophers->AddItem(plato);
16 
17     JsonObject* socrates = new JsonObject();
18     result = socrates->AddField("name", new JsonString(u"Socrates"));
19     if (result.Error()) return Result<UniquePtr<JsonArray>>(ErrorId(result.GetErrorId()));
20     philosophers->AddItem(socrates);
21     return Result<UniquePtr<JsonArray>>(UniquePtr<JsonArray>(philosophers));
22 }
23 
24 int main()
25 {
26     Result<UniquePtr<JsonArray>> philosopherResult = MakePhilosophers();
27     if (philosopherResult.Error())
28     {
29         Console.Error() << philosopherResult.GetErrorMessage() << endl();
30         return 1;
31     }
32     JsonArray* philosophers = philosopherResult.Value().Get();
33     System.Text.CodeFormatter formatter(Console.Out());
34     auto result = philosophers->Write(formatter);
35     if (result.Error())
36     {
37         Console.Error() << result.GetErrorMessage() << endl();
38         return 1;
39     }
40     Result<string> toStringResult = philosophers->ToString();
41     if (toStringResult.Error())
42     {
43         Console.Error() << toStringResult.GetErrorMessage() << endl();
44         return 1;
45     }
46     string json = Rvalue(toStringResult.Value());
47     Console.Out() << json << endl();
48     Result<UniquePtr<JsonValue>> parseResult = ParseJson(json);
49     if (parseResult.Error())
50     {
51         Console.Error() << parseResult.GetErrorMessage() << endl();
52         return 1;
53     }
54     JsonValue* jsonValue = parseResult.Value().Get();
55     if (jsonValue is JsonArray*)
56     {
57         JsonArray* a = cast<JsonArray*>(jsonValue);
58         long n = a->Count();
59         for (long i = 0; i < n; ++i;)
60         {
61             JsonValue* item = a->GetItem(i);
62             if (item is JsonObject*)
63             {
64                 JsonObject* o = cast<JsonObject*>(item);
65                 Result<JsonValue*> vr = o->GetField("name");
66                 if (vr.Error())
67                 {
68                     Console.Error() << vr.GetErrorMessage() << endl();
69                     return 1;
70                 }
71                 JsonValue* v = vr.Value();
72                 if (v != null)
73                 {
74                     if (v is JsonString*)
75                     {
76                         JsonString* s = cast<JsonString*>(v);
77                         Console.Out() << s->Value() << endl();
78                     }
79                     else
80                     {
81                         Console.Error() << "JSON string expected" << endl();
82                         return 1;
83                     }
84                 }
85                 else
86                 {
87                     Console.Error() << "\'name\' field not found" << endl();
88                     return 1;
89                 }
90             }
91         }
92     }
93     else
94     {
95         Console.Error() << "JSON array expected" << endl();
96         return 1;
97     }
98     return 0;
99 }