Method type

Src/Data/Myc.Data.Types.Method.pas

@@ -0,0 +1,136 @@
+unit Myc.Data.Types.Method;
+
+interface
+
+uses
+    System.SysUtils,
+    System.Rtti,
+    Myc.Data.Types;
+
+type
+    // Implements the IDataMethodType interface.
+    // This class is now instantiated for each unique method signature.
+    TDataMethodType = class(TInterfacedObject, IDataMethodType)
+    private
+        FArgType: IDataType;
+        FResultType: IDataType;
+        function GetName: String;
+        function GetKind: TDataKind;
+        function GetArgType: IDataType;
+        function GetResultType: IDataType;
+        function CreateValue(const AValue: TMethodProc): IDataMethodValue;
+    public
+        // The constructor now takes the signature types.
+        constructor Create(const AArgType, AResultType: IDataType);
+    end;
+
+implementation
+
+uses
+    System.Classes;
+
+type
+    // Implements the IDataMethodValue interface.
+    TDataMethodValue = class(TInterfacedObject, IDataMethodValue)
+    private
+        FDataType: IDataMethodType;
+        FValue: TMethodProc;
+        function GetDataType: IDataType;
+        function GetAsString: string;
+        function AsTValue: TValue;
+        function GetValue: TMethodProc;
+    public
+        constructor Create(const ADataType: IDataMethodType; const AValue: TMethodProc);
+    end;
+
+{ TDataMethodType }
+
+constructor TDataMethodType.Create(const AArgType, AResultType: IDataType);
+begin
+    inherited Create;
+    FArgType := AArgType;
+    FResultType := AResultType;
+end;
+
+function TDataMethodType.CreateValue(const AValue: TMethodProc): IDataMethodValue;
+begin
+    if not Assigned(AValue) then
+        raise EArgumentException.Create('AValue');
+
+    // Pass Self to the value's constructor, so it knows its exact type
+    Result := TDataMethodValue.Create(Self, AValue);
+end;
+
+function TDataMethodType.GetArgType: IDataType;
+begin
+    Result := FArgType;
+end;
+
+function TDataMethodType.GetResultType: IDataType;
+begin
+    Result := FResultType;
+end;
+
+function TDataMethodType.GetKind: TDataKind;
+begin
+    Result := dkMethod;
+end;
+
+function TDataMethodType.GetName: String;
+var
+    sb: TStringBuilder;
+    argName, resultName: string;
+begin
+    if Assigned(FArgType) then
+        argName := FArgType.Name
+    else
+        argName := 'Void';
+
+    if Assigned(FResultType) then
+        resultName := FResultType.Name
+    else
+        resultName := 'Void';
+
+    sb := TStringBuilder.Create;
+    try
+        sb.Append('Method<');
+        sb.Append(argName);
+        sb.Append(' -> ');
+        sb.Append(resultName);
+        sb.Append('>');
+        Result := sb.ToString;
+    finally
+        sb.Free;
+    end;
+end;
+
+{ TDataMethodValue }
+
+constructor TDataMethodValue.Create(const ADataType: IDataMethodType; const AValue: TMethodProc);
+begin
+    inherited Create;
+    FDataType := ADataType;
+    FValue := AValue;
+end;
+
+function TDataMethodValue.GetDataType: IDataType;
+begin
+    Result := FDataType;
+end;
+
+function TDataMethodValue.GetAsString: string;
+begin
+    Result := '<METHOD>';
+end;
+
+function TDataMethodValue.AsTValue: TValue;
+begin
+    Result := TValue.From<TMethodProc>(FValue);
+end;
+
+function TDataMethodValue.GetValue: TMethodProc;
+begin
+    Result := FValue;
+end;
+
+end.