All Questions
85 questions
1
vote
2
answers
338
views
How to change keys from a map in scala
How to change the following keys from the map without any variables full functional
HashMap(false -> List(20, 15, 20, 17), true -> List(50, 25, 45, 21, 100, 2000, 2100))
to
HashMap("...
- 49
0
votes
0
answers
52
views
How to rotate a 90-degree asymmetric matrix using Scala recursion [duplicate]
I'm writing a simple anomaly detector for time-series data in Scala.
I need to rotate a matrix by 90 degrees or find a better way to have a map[String,Vector[Double] that holds the data.
I get the ...
- 13
0
votes
2
answers
225
views
How to unwind an object based on deeply nested list fields in scala?
Simplified Scenario
Lets take a simplified example with 2 levels of nested fields in a case class.
Suppose I have a case class Person as shown below:
case class Address(
name: String,
zipCodes: ...
- 6,578
1
vote
1
answer
552
views
Play framework: Why does https url not work on using "sbt dist" command?
I am trying to create executable file for deploying my web app using play framework sbt dist command. When I run my application using "sbt run" command then https work but when I use sbt dist and run ...
- 317
-2
votes
2
answers
135
views
How to use val instead of var in scala
I simply want to remove var and use Val instead in below code
def getConfigId: Long = {
val object1: java.util.List[objectA] = objectRepo.findByUser(User(session.id))
var object2: objectA = null
if (...
- 143
3
votes
0
answers
6k
views
How to perform a `Collectors.toList()` correspondingly in scala
I have the following class and method used in the code below with ids being a Set[String]:
case class PAV ()
def aggregate(pId: String, iId: Option[String], count: Int): PAV
I have tried the ...
- 32.2k
2
votes
2
answers
2k
views
What's the best way to retrieve the value in a nullable Optional?
Suppose you have an Optional<T> variable that could take on one of 3 values:
the value T
an Optional with a null T in it
the variable is null itself
What's the best way to retrieve the value T ...
- 6,037
4
votes
3
answers
4k
views
Functional Programming vs OOP [closed]
I just looked up a few examples/definitions of the differences between Functional Programming and OOP. I found one definition that I thought was interesting and I understood the OOP part but needed a ...
- 1,327
0
votes
1
answer
15k
views
Scala compile time error: No implicits found for parameter evidence$2: BodyWritable[Map[String, Object]]
I am working on scala play framework application. I am trying to call a web service API which takes request payload data as follows
{
"toID": [
"[email protected]",
"email2@email....
- 317
0
votes
1
answer
473
views
How to pass optional parameters while accessing web service API in play framework?
I am new to play framework and trying to integrate a microservice. I am using WSClient to call a web service. In order to call a POST rest API, I am passing request body which contains some required ...
- 317
2
votes
1
answer
212
views
How to export Scala Transformation to Java
I'm trying to implement a Scala trait by Java, the trait has a generic container type within another container, which couldn't be solved automatically by java import, the Scala code is below:
import ...
- 568
1
vote
1
answer
557
views
Scala Fold Left with Two Parameter Types
How can I convert this basic function func2 into a fold left in Scala?
Here is the iterative approach. I use two functions.
def func1(list1: List[foo], item: bar): List[foo] = {
does something ...
-3
votes
1
answer
93
views
Functional Data structures to support flow control
I'd like to find a functional data structure that can perform "Flow control".
Example: For any IP visiting my website, if the IP has visited >= N times since M minutes ago, the IP is restricted to ...
- 21
1
vote
4
answers
3k
views
scala class members causing error "Class 'class' must either be declared abstract or implement member 'member' "
I am trying to learn Scala Objects and Class. I come from Java which is quite similar to Scala, but not in syntax.
In Java, I would create a class like:
public class Wallet {
private PublicKey ...
- 2,436
4
votes
1
answer
636
views
scala count strings in a list contained in a read file
I am new to SO but have spent days going through related to questions. The closest related question I found is How to compare each word of a line in a file with a list element in scala? but that goes ...
- 43