Force specific decimal separator using the f string interpolator in Scala

Question

I'm trying to compose a formatted string that should look like this:

A bottle of vodka costs x.yz rubles.

where x.yz is an arbitrary Double value rounded to 2 decimal signs.

To achieve this, I use string interpolation with printf syntax:

val cost = 2.56
val str = f"A bottle of vodka costs $cost%.2f rubles."

Unfortunately, on a machine with Russian locale, the snippet above yields a result that is a bit different from what I want to achieve:

str: String = A bottle of vodka costs 2,56 rubles.

This is understandable (the Java formatter used by f interpolator applies the locale-specific decimal separator, as outlined here ), but I still want to use decimal dot instead of comma.

I'm aware of a possible workaround – using the formatLocal() method with explicitly set locale:

 val str = "A bottle of vodka costs %.2f  rubles.".formatLocal(java.util.Locale.US, cost)

but it does not strike me as a particularly Scalaesque way of doing things.

So my question is this: is it possible to format a string with a specific decimal separator using only f interpolation, without any extraneous method calls?

Answer 1

目前， f插补器不支持语言环境或自定义分隔符（请参阅macro_StringInterpolation_f.scala / FastTrack.scala ）。