Option in the Scala language is a container for zero or one element of a given type.
Option in scala is a container for zero or one element of a given type.
Questions tagged [scala-option]
232 questions
0
votes
2 answers
Type mismatch required: Option[Any] => Option[Nothing]
How can I fix this type error?
object Test extends App {
def printOption[A](a: Option[A]): Option[A] = { println(a getOrElse("none")); a }
def printHashCodeAndMap[A, B](fn: Option[A] => Option[B], list: List[Option[A]]): List[Option[B]] = {
…
Adrian
- 3,762
- 2
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0
votes
2 answers
How to get the class of Option[_] on a None with Reflection
I have this setup where I want to populate an object fields from an XML NodeSeq. A cutdown version of my setup is shown. It works well, but when I put None in testObj, I get a java.util.NoSuchElementException: None.get.
The problem I believe is that…
user1899790
- 21
- 2
0
votes
3 answers
Applying or operation to Option results
I have the following code:
class CSplit(var s1: CanvNode, var s2: CanvNode) extends SplitPane
{
topComponent = s1.merge
bottomComponent = s2.merge
def containsV(orig: MapCanvT): Option[MapCanvT] =
{
def containsIn(cn:…
Rich Oliver
- 6,001
- 4
- 34
- 57
-1
votes
1 answer
Scala: optional sequence of arguments
Here's some data:
val data = List(1,1,2,2,3)
I would like to write a function filteredSum which supports the following:
/*1*/ filteredSum(data) // Outputs 0
/*2*/ filteredSum(data, 1) // Outputs 1 + 1 = 2
/*3*/ filteredSum(data, 1, 3) // Outputs 1…
Paul Siegel
- 1,401
- 13
- 36
-1
votes
1 answer
None, Some and conditional treatments
I would like to accomplish this:
A variable named abc must be None, except if the result of complicated treatments is true.
I wrote a beginning of and answer but it doesn't work:
def…
lolveley
- 1,659
- 2
- 18
- 34
-2
votes
2 answers
Need to get the list from Option Vector
I have a vector of option of List of Tuple
like
val x = Vector(
Some(List(("x",2))),
Some(List(("x",2),("y",3))),
None,
Some(List(("x",2),("z",2))),
Some(List(("x",2),("z",2))),
None)
How to get the list from the above vector
Updated:
The final…
user7097216
-3
votes
4 answers
How can I add each element in first list with the corresponding list in Scala?
So I have a list so:
var data = List(
List(Some(313.062468), Some(27.847252), Some(29.847252)),
List(Some(301.873641), Some(42.884065), Some(89.847252)),
List(Some(332.373186), Some(53.509768), Some(10.847252))
)
How can I…
S. Nas
- 331
- 1
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