I am new to Scala, and I tried to generate some Range objects.
val a = 0 to 10
// val a: scala.collection.immutable.Range.Inclusive = Range 0 to 10
This statement works perfectly fine and generates a range from 0 to 10. And to keyword works without any imports.
But when I try to generate a NumericRange with floating point numbers, I have to import some functions from BigDecimal object as follows, to use to keyword.
import scala.math.BigDecimal.double2bigDecimal
val f = 0.1 to 10.1 by 0.5
// val f: scala.collection.immutable.NumericRange.Inclusive[scala.math.BigDecimal] = NumericRange 0.1 to 10.1 by 0.5
Can someone explain the reason for this and the mechanism behind range generation. Thank you.
The import you are adding adds "automatic conversion" from Double to BigDecimal as the name suggests.
It's necessary because NumericRange only works with types T for which Integral[T] exists and unfortunately it doesn't exist for Double but exists for BigDecimal.
Bringing tha automatic conversion in scope makes the Doubles converted in BigDecimal so that NumericRange can be applied/defined.
You could achieve the same range without the import by declaring directly the numbers as BigDecimals:
BigDecimal("0.1") to BigDecimal("10.1") by BigDecimal("0.5")