function TGraphQLJson.ASTValueToJSON(Value: TASTValue): TJsonValue;
var
  I: Integer;
begin
  Result := nil;
  try
    if Value is TASTListValue then
    begin
      Result := TJsonArray.Create;
      for I := 0 to TASTListValue(Value).Count - 1  do
        TJsonArray(Result).AddElement(ASTValueToJSON(TASTListValue(Value).Items[I]));
    end;

    if Value is TASTObjectValue then
    begin
      Result := TJsonObject.Create;
      for I := 0 to TASTObjectValue(Value).Count - 1 do
        TJsonObject(Result).AddPair(TASTObjectValue(Value).Items[I].Name, ASTValueToJSON(TASTObjectValue(Value).Items[I].Value));
    end;


    if Value is TASTStringValue then
      Result := TJsonString.Create(TASTStringValue(Value).Value);

    if Value is TASTIntValue then
      Result := TJsonNumber.Create(TASTIntValue(Value).Value);

    if Value is TASTNullValue then
      Result := TJsonString.Create;

    if Value is TASTBooleanValue then
      Result := TJsonBool.Create(TASTBooleanValue(Value).Value <> 'false');

    if Value is TASTFloatValue then
      Result := TJsonNumber.Create(TASTFloatValue(Value).Value);
  except
    Result.Free;
    raise;
  end;
end;

constructor TGraphQLJson.Create;
begin
  inherited Create('JSON');
end;

function TGraphQLJson.ParseLiteral(Value: TASTValue): TValue;
var
  JsonValue: TJsonValue;
begin
  JsonValue := ASTValueToJSON(Value);
  Result := TValue.From<TJsonValue>(JsonValue);
end;