implicit Questions
2
Solved
Currently learning about Scala 3 implicits but I'm having a hard time grasping what the as and with keywords do in a definition like this:
given listOrdering[A](using ord: Ordering[A]) as Ordering...
2
Solved
Suppose that I have some typeclass
trait FooBar[X]
and an instance of FooBar[Int]:
given intIsFooBar: FooBar[Int] = new FooBar {}
Now, suppose that I have an interface Intf that has some member t...
Virgil asked 21/3, 2023 at 21:31
5
I am just curious to understand JSON and Dict in Python more deeply.
I have a JSON response from a server like this:
`{"city":"Mississauga","country":"Canada","countryCode":"CA"}`
And I want to...
Quidnunc asked 11/8, 2016 at 0:4
2
Solved
Taken from "Scala with cats" (page 18):
Implicit Conversions
When you create a type class instance constructor using an implicit def, be sure to mark the parameters to the method as impl...
Byler asked 5/12, 2020 at 15:33
5
This is tiny snippet of my code.
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <time.h>
#include <sys/stat.h>
#include <sys/wait.h>
...
Higinbotham asked 29/3, 2011 at 5:37
9
Solved
I'm new to C# and learning new words. I find it difficult to understand what's the meaning of these two words when it comes to programming c#.
I looked in the dictionary for the meaning and here's...
Fisticuffs asked 24/7, 2009 at 9:39
4
Solved
The following C# program silently and implicitly calls an explicit decimal-to-long conversion operator, losing precision.
I don't understand why this happens. As far as I understand, in C# ex...
Colvert asked 25/5, 2023 at 20:47
8
I am attempting to get the implicit flow working for IdentityServer4. Login and logout work correctly, however the PostLogoutRedirectUri is coming back null, despite setting the value where it need...
Massey asked 21/6, 2017 at 19:24
2
Solved
This is a simple example:
object CoerciveCovariance {
trait Cov[+T]
def cast[A, B](v: Cov[A])(
implicit
ev: A <:< B
) = {
v: Cov[B]
}
}
It doesn't compile:
CoerciveCovariance.scala...
Vaasta asked 16/3, 2023 at 22:51
1
Considering the following code:
import scala.reflect.api.Universe
object UnqualifiedTypeTag {
val RuntimeUniverse = scala.reflect.runtime.universe
trait HasUniverse {
val universe: Universe ...
Polyneuritis asked 20/2, 2023 at 2:58
1
Solved
I have a scenario where I would like to call sum on a sequence of (Double, Double) tuples.
Ideally I would like to do something like the following:
implicit def toTupleNumeric[T](num: Numeric[T]) =...
Nikaniki asked 15/2, 2023 at 11:14
5
Solved
What I am trying to do is to make a function that would take a generic class and use a static method in it (sorry for Java language, I mean method of its companion object).
trait Worker {def doSth...
2
Solved
The title might be quite vague, but here is the code: https://github.com/amorfis/why-no-implicit
So there is a tool to transform Map[String, Any] to a simple case class. The tests pass and this pie...
1
Solved
given:
sealed trait Data
final case class Foo() extends Data
final case class Bar() extends Data
final case class TimestampedData[A <: Data](data: A, timestamp: Long)
Is there a succint way to...
Vitiated asked 14/11, 2022 at 10:27
2
Solved
So, importing an implicit member from a created instance works as expected,
object Test extends App {
class Bag {
implicit val ssss: String = "omg"
}
def call(): Unit = {
val bag = ...
Spectroscopy asked 8/11, 2022 at 14:12
1
I'm new to Scala, and using circe to model and serialize some API responses.
I find myself using the following boilerplate
sealed trait SomeTrait
object SomeTrait {
implicit val someEncoder: Enco...
1
Solved
2
Solved
I've been doing derivatives in sympy, and I didn't know how that would syntactically be written. I tried looking it up, but none of the solutions made sense. For example, if I'm trying to different...
Rudich asked 17/2, 2016 at 5:59
2
Solved
tl;dr: How do I do something like the made up code below:
def notFunctor[M[_] : Not[Functor]](m: M[_]) = s"$m is not a functor"
The 'Not[Functor]', being the made up part here.
I want it to su...
Stanzel asked 12/4, 2013 at 3:51
1
Solved
I am reading the Scrap Your Boilerplate paper and trying to follow along by implementing the ideas in scala as best I can. However, I'm stuck on the very first function, the cast, which is used to ...
Unnecessary asked 21/10, 2022 at 4:6
1
I have many value classes that make up a larger object case class.
final case class TopLevel(
foo: Foo,
bar: Bar
)
final case class Foo(foo: String) extends AnyVal
final case class Bar(bar: Str...
Spiroid asked 10/3, 2022 at 14:35
1
I want to leverage Scala reflection to implicitly pass a ClassTag.
There are plenty solutions on StackOverflow on how to accomplish this.
import scala.reflect.ClassTag
// animal input
trait Animal...
Liberati asked 25/9, 2022 at 18:8
1
Solved
I am generating the Scala code shown below using the openapi-generator.
import examples.openverse.model.{InlineObject, OAuth2RegistrationSuccessful}
import examples.openverse.core.JsonSupport._
imp...
Torque asked 14/9, 2022 at 6:26
2
Solved
I have a trait with a self-type annotation that has a type parameter. This trait is from a library and cannot be modified. I want to pass this trait to a function that will require an upper bound f...
Albania asked 9/9, 2022 at 4:46
1
Continuing What is "prolog style" in Scala?
I want to combine logical inference and procedural code, in Scala-3. Something like this:
// This is a mix of Prolog and Scala, and is not a re...
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