public class Car { private int maxSpeed; public Car(int maxSpeed) { this.maxSpeed = maxSpeed; } public int getMaxSpeed() { return maxSpeed; } } We can sort a list of cars by, Car carX = new Car(155); Car carY = new Car(140); List<Car> cars = new ArrayList<>(); cars.add(carX); cars.add(carY); cars.sort(Comparator.comparing(Car::getMaxSpeed)); If we see the signature of … Read more
I’ve made Lambda functions before but not in Python. I know in Javascript Lambda supports the handler function being asynchronous, but I get an error if I try it in Python. Here is the code I am trying to test: async def handler(event, context): print(str(event)) return { ‘message’ : ‘OK’ } And this is the … Read more
Like we all know, it’s not that easy to break from a nested loop out of an outer loop without either: a goto (Example code.) another condition check in the outer loop (Example code.) putting both loops in an extra function and returning instead of breaking (Example code.) Though, you gotta admit, all of those … Read more
I have no doubt this is as easy to do as possible, but I have a function creator library that creates lambda functions for me of the form: Func<T1, object> And I’m looking to specify the out parameter more specifically – Basically, I’m looking to be able to create something along the lines of: private … Read more
I’m using ES6, babel and Webpack 2 to bundle an AWS Lambda. I am then running/testing it using AWS SAM local. I get the following error when I hit the api – Handler ‘handler’ missing on module ‘dist/main’ Here is my webpack.config.js – const path = require(‘path’); module.exports = { entry: ‘./index.js’, output: { path: … Read more
https://docs.aws.amazon.com/AWSSimpleQueueService/latest/APIReference/API_SendMessage.html https://sqs.us-east-2.amazonaws.com/123456789012/MyQueue/ ?Action=SendMessage &MessageBody=This+is+a+test+message This works fine, however is it possible to send the payload using the post body? I have an external service sending json payloads in the post body (at a very high throughput). It would be ideal if I can simply feed them the SQS url directly, and avoid having to create … Read more
I’ve found a strange behavior using polymorphic C++14 lambdas (lambdas with auto in their parameters): Snippet 0: #include <iostream> template<typename T> void doLambda(T&& mFn) { std::forward<T>(mFn)(int{0}); } template<typename T> void test(T&& mV) { doLambda([&mV](auto mE) { std::forward<decltype(mV)>(mV); }); } int main() { test(int{0}); return 0; } clang++ 3.5.1: the snippet compiles and runs successfully. g++ … Read more
I am concerned about security. The creation of IAM Roles is a high security risk, and the fact that you can only specify to be AWS Lambda the one that can assume a role is not good enough IMO. There could be a privilege escalation if not treated with care. How can I create IAM … Read more
I have AWS API gateway setup for a public endpoint with no auth. It connects to a websocket that triggers a Lambda. I was creating connections with Python’s websocket-client lib at https://pypi.org/project/websocket_client/. I noticed that connections would fail ~10% of the time, and get worse as I increased load. I can’t find anywhere that would … Read more
Strange behavior of DLR. I have a method accepts two arguments: dynamic and Func<>. When I pass only dynamic OR only Func<> – no errors. But when I try to pass these arguments at same time – appears error “Cannot use a lambda expression as an argument to a dynamically dispatched operation without first casting … Read more
