A less known builtin feature is Controller Action injection using the FromServicesAttribute.
[HttpGet]
public async Task<IActionResult> GetAllAsync([FromServices]IProductService products)
{
return Ok(await products.GetAllAsync());
}
An important note is that the [FromServices] c...
Element and attribute names live in namespaces that are URIs. Namespaces are bound to prefixes that are used in the actual element and attribute names, which are called QNames.
This document binds a namespace to the prefix prefix and defines a default namespace, bound with the absence of prefix.
&...
Given a Person struct
struct Person {
let name: String
let birthYear: Int?
}
and an Array of Person(s)
let persons = [
Person(name: "Walter White", birthYear: 1959),
Person(name: "Jesse Pinkman", birthYear: 1984),
Person(name: "Skyler White&quo...
HTTP describes how an HTTP client, such as a web browser, sends an HTTP request via a network to an HTTP server, which then sends an HTTP response back to the client.
The HTTP request is typically either a request for an online resource, such as a web page or image, but may also include additiona...
Cheatsheet
DODON'TControl flow with control statementsControl flow with exceptionsKeep track of ignored (absorbed) exception by loggingIgnore exceptionRepeat exception by using throwRe-throw exception - throw new ArgumentNullException() or throw exThrow predefined system exceptionsThrow custom exce...
Retrofit2 comes with support for multiple pluggable execution mechanisms, one of them is RxJava.
To use retrofit with RxJava you first need to add the Retrofit RxJava adapter to your project:
compile 'com.squareup.retrofit2:adapter-rxjava:2.1.0'
then you need to add the adapter when building yo...
You can use the zip operator to make request in parallel and combine the results eg:
Observable.zip(api.getRepo(repoId1), api.getRepo(repoId2), (repo1, repo2) ->
{
//here you can combine the results
}).subscribe(/*do something with the result*/);
C++11 introduced core language and standard library support for moving an object. The idea is that when an object o is a temporary and one wants a logical copy, then its safe to just pilfer o's resources, such as a dynamically allocated buffer, leaving o logically empty but still destructible and co...
Placeholders allow you to feed values into a tensorflow graph. Aditionally They allow you to specify constraints regarding the dimensions and data type of the values being fed in. As such they are useful when creating a neural network to feed new training examples.
The following example declares a ...
To perform elementwise multiplication on tensors, you can use either of the following:
a*b
tf.multiply(a, b)
Here is a full example of elementwise multiplication using both methods.
import tensorflow as tf
import numpy as np
# Build a graph
graph = tf.Graph()
with graph.as_default():
...
The dot product between two tensors can be performed using:
tf.matmul(a, b)
A full example is given below:
# Build a graph
graph = tf.Graph()
with graph.as_default():
# A 2x3 matrix
a = tf.constant(np.array([[1, 2, 3],
[2, 4, 6]]),
...
Type synonym families are just type-level functions: they associate parameter types with result types. These come in three different varieties.
Closed type-synonym families
These work much like ordinary value-level Haskell functions: you specify some clauses, mapping certain types to others:
{-# ...
Data families can be used to build datatypes that have different implementations based on their type arguments.
Standalone data families
{-# LANGUAGE TypeFamilies #-}
data family List a
data instance List Char = Nil | Cons Char (List Char)
data instance List () = UnitList Int
In the above de...
XSS attacks consist in injecting HTML (or JS) code in a page. See What is cross site scripting for more information.
To prevent from this attack, by default, Django escapes strings passed through a template variable.
Given the following context:
context = {
'class_name': 'large" style=&...
You can use raycasts to check if an ai can walk without falling off the edge of a level.
using UnityEngine;
public class Physics2dRaycast: MonoBehaviour
{
public LayerMask LineOfSightMask;
void FixedUpdate()
{
RaycastHit2D hit = Physics2D.Raycas...
A Bag/ultiset stores each object in the collection together with a count of occurrences. Extra methods on the interface allow multiple copies of an object to be added or removed at once. JDK analog is HashMap<T, Integer>, when values is count of copies this key.
TypeGuavaApache Commons Collec...
This multimap allows duplicate key-value pairs. JDK analogs are HashMap<K, List>, HashMap<K, Set> and so on.
Key's orderValue's orderDuplicateAnalog keyAnalog valueGuavaApacheEclipse (GS) CollectionsJDKnot definedInsertion-orderyesHashMapArrayListArrayListMultimapMultiValueMapFastListMu...
Compare operation with collections - Create collections
1. Create List
DescriptionJDKguavags-collectionsCreate empty listnew ArrayList<>()Lists.newArrayList()FastList.newList()Create list from valuesArrays.asList("1", "2", "3")Lists.newArrayList("1", &...
Suppose we want to count how many counties are there in Texas:
var counties = dbContext.States.Single(s => s.Code == "tx").Counties.Count();
The query is correct, but inefficient. States.Single(…) loads a state from the database. Next, Counties loads all 254 counties with all of the...
