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| 1 | +using System.Text; |
| 2 | + |
| 3 | +using ExtensibleParaser; |
| 4 | + |
| 5 | +namespace Json; |
| 6 | + |
| 7 | +public class JsonVisitor(string input) : ISyntaxVisitor |
| 8 | +{ |
| 9 | + public JsonAst? Result { get; private set; } |
| 10 | + |
| 11 | + public void Visit(TerminalNode node) |
| 12 | + { |
| 13 | + var span = node.AsSpan(input).ToString(); |
| 14 | + Result = node.Kind switch |
| 15 | + { |
| 16 | + "String" => new JsonString(ProcessJsonString(span[1..^1]), node.StartPos, node.EndPos), |
| 17 | + "Number" => new JsonNumber(double.Parse(span), node.StartPos, node.EndPos), |
| 18 | + "True" => new JsonBoolean(true, node.StartPos, node.EndPos), |
| 19 | + "False" => new JsonBoolean(false, node.StartPos, node.EndPos), |
| 20 | + "Null" => new JsonNull(node.StartPos, node.EndPos), |
| 21 | + "{" or "}" or "[" or "]" or ":" or "," => null, // Игнорируем литералы-символы |
| 22 | + _ => throw new InvalidOperationException($"Unknown terminal: {node.Kind}") |
| 23 | + }; |
| 24 | + } |
| 25 | + |
| 26 | + public void Visit(SeqNode node) |
| 27 | + { |
| 28 | + var children = new List<JsonAst>(); |
| 29 | + foreach (var element in node.Elements) |
| 30 | + { |
| 31 | + element.Accept(this); |
| 32 | + if (Result != null) |
| 33 | + children.Add(Result); |
| 34 | + } |
| 35 | + |
| 36 | + Result = node.Kind switch |
| 37 | + { |
| 38 | + "Object" => HandleObjectNode(children, node), |
| 39 | + "Property" => HandlePropertyNode(children, node), |
| 40 | + "Array" => HandleArrayNode(children, node), |
| 41 | + _ => throw new InvalidOperationException($"Unknown sequence: {node.Kind}") |
| 42 | + }; |
| 43 | + } |
| 44 | + |
| 45 | + public void Visit(ListNode node) |
| 46 | + { |
| 47 | + var elements = new List<JsonAst>(); |
| 48 | + foreach (var element in node.Elements) |
| 49 | + { |
| 50 | + element.Accept(this); |
| 51 | + if (Result != null) |
| 52 | + elements.Add(Result); |
| 53 | + } |
| 54 | + |
| 55 | + Result = node.Kind switch |
| 56 | + { |
| 57 | + "Properties" => new JsonObject(elements.OfType<JsonProperty>().ToList(), node.StartPos, node.EndPos), |
| 58 | + "Elements" => new JsonArray(elements, node.StartPos, node.EndPos), |
| 59 | + _ => throw new InvalidOperationException($"Unknown list: {node.Kind}") |
| 60 | + }; |
| 61 | + } |
| 62 | + |
| 63 | + public void Visit(SomeNode node) => node.Value.Accept(this); |
| 64 | + |
| 65 | + public void Visit(NoneNode _) => Result = null; |
| 66 | + |
| 67 | + private JsonObject HandleObjectNode(List<JsonAst> children, SeqNode node) |
| 68 | + { |
| 69 | + if (children.Count == 1 && children[0] is JsonObject propertiesObject) |
| 70 | + return new JsonObject(propertiesObject.Properties, node.StartPos, node.EndPos); |
| 71 | + else |
| 72 | + return new JsonObject(children.OfType<JsonProperty>().ToArray(), node.StartPos, node.EndPos); |
| 73 | + } |
| 74 | + |
| 75 | + private JsonProperty HandlePropertyNode(List<JsonAst> children, SeqNode node) |
| 76 | + { |
| 77 | + if (children is [JsonString key, JsonAst value]) |
| 78 | + return new JsonProperty(key.Value, value, node.StartPos, node.EndPos); |
| 79 | + |
| 80 | + throw new InvalidOperationException($"Invalid property structure. Expected [String, Value], got [{string.Join(", ", children.Select(c => c.GetType().Name))}]"); |
| 81 | + } |
| 82 | + |
| 83 | + private JsonArray HandleArrayNode(List<JsonAst> children, SeqNode node) |
| 84 | + { |
| 85 | + if (children.Count == 1 && children[0] is JsonArray elementsArray) |
| 86 | + return new JsonArray(elementsArray.Elements, node.StartPos, node.EndPos); |
| 87 | + else |
| 88 | + return new JsonArray(children.Where(c => c is not JsonObject).ToArray(), node.StartPos, node.EndPos); |
| 89 | + } |
| 90 | + |
| 91 | + private static string ProcessJsonString(string input) |
| 92 | + { |
| 93 | + var result = new StringBuilder(); |
| 94 | + for (int i = 0; i < input.Length; i++) |
| 95 | + { |
| 96 | + if (input[i] == '\\' && i + 1 < input.Length) |
| 97 | + { |
| 98 | + switch (input[i + 1]) |
| 99 | + { |
| 100 | + case '"': result.Append('"'); i++; break; |
| 101 | + case '\\': result.Append('\\'); i++; break; |
| 102 | + case '/': result.Append('/'); i++; break; |
| 103 | + case 'b': result.Append('\b'); i++; break; |
| 104 | + case 'f': result.Append('\f'); i++; break; |
| 105 | + case 'n': result.Append('\n'); i++; break; |
| 106 | + case 'r': result.Append('\r'); i++; break; |
| 107 | + case 't': result.Append('\t'); i++; break; |
| 108 | + case 'u' when i + 5 < input.Length: |
| 109 | + var hex = input.Substring(i + 2, 4); |
| 110 | + result.Append((char)Convert.ToInt32(hex, 16)); |
| 111 | + i += 5; |
| 112 | + break; |
| 113 | + default: result.Append(input[i + 1]); i++; break; |
| 114 | + } |
| 115 | + } |
| 116 | + else |
| 117 | + result.Append(input[i]); |
| 118 | + } |
| 119 | + |
| 120 | + return result.ToString(); |
| 121 | + } |
| 122 | +} |
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