Use record instead of class for LSP types.

generator/plugins/dotnet/custom/OrType.cs

@@ -1,6 +1,6 @@
 using System;
 
-public class OrType<T, U> : IOrType
+public record OrType<T, U> : IOrType
 {
     public object? Value { get; }
     public OrType(T t)
@@ -32,7 +32,7 @@ public override string ToString()
     }
 }
 
-public class OrType<T, U, V> : IOrType
+public record OrType<T, U, V> : IOrType
 {
     public object? Value { get; }
 
@@ -79,7 +79,7 @@ public override string ToString()
 }
 
 
-public class OrType<T, U, V, W> : IOrType
+public record OrType<T, U, V, W> : IOrType
 {
     public object? Value { get; }
 

generator/plugins/dotnet/dotnet_classes.py

@@ -219,12 +219,10 @@ def generate_property(
 
     if prop_def.type.kind == "stringLiteral":
         lines.append(
-            f'public {type_name}{optional} {name} {{ get; set; }} = "{prop_def.type.value}";'
+            f'public {type_name}{optional} {name} {{ get; init; }} = "{prop_def.type.value}";'
         )
-    elif prop_def.type.kind == "base" and prop_def.type.name == "null":
-        lines.append(f"public {type_name}{optional} {name} {{ get; set; }} = null;")
     else:
-        lines.append(f"public {type_name}{optional} {name} {{ get; set; }}")
+        lines.append(f"public {type_name}{optional} {name} {{ get; init; }}")
 
     usings.append("DataMember")
     if converter:

generator/plugins/dotnet/dotnet_helpers.py

@@ -108,19 +108,23 @@ def class_wrapper(
     inner: List[str],
     derived: Optional[str] = None,
     class_attributes: Optional[List[str]] = None,
+    is_record=True,
 ) -> List[str]:
     if hasattr(type_def, "name"):
         name = get_special_case_class_name(type_def.name)
     else:
         raise ValueError(f"Unknown type: {type_def}")
 
+    rec_or_cls = "record" if is_record else "class"
     lines = (
         get_doc(type_def.documentation)
         + generate_extras(type_def)
         + (class_attributes if class_attributes else [])
         + [
             "[DataContract]",
-            f"public class {name}: {derived}" if derived else f"public class {name}",
+            f"public {rec_or_cls} {name}: {derived}"
+            if derived
+            else f"public {rec_or_cls} {name}",
             "{",
         ]
     )

generator/plugins/dotnet/dotnet_special_classes.py

@@ -45,6 +45,7 @@ def generate_special_class(
                 ["public LSPObject(Dictionary<string, object?> value):base(value){}"],
                 "Dictionary<string, object?>",
                 ["[JsonConverter(typeof(CustomObjectConverter<LSPObject>))]"],
+                is_record=False,
             ),
         )
     if type_def.name == "InitializedParams":
@@ -58,6 +59,7 @@ def generate_special_class(
                 ],
                 "Dictionary<string, object?>",
                 ["[JsonConverter(typeof(CustomObjectConverter<InitializedParams>))]"],
+                is_record=False,
             ),
         )
     if type_def.name == "LSPAny":
@@ -82,6 +84,7 @@ def generate_special_class(
                 type_def,
                 ["public LSPArray(List<object> value):base(value){}"],
                 "List<object>",
+                is_record=False,
             ),
         )