Defaults for map

[jimka]

@BalmungSan

Or keep using withDefault the thing is, the returned Map will have the default which may not be what you want.

Do we know which situations the resulting Map has the correct default and in which cases it has the incorrect default? In my very simple test using + to add to a Map the default is retained correctly.

val m1 = Map("a" -> 1).withDefaultValue(Set())
val m2 = m1 + ("b" -> 2)
m2("") // returns Set()

val m3 = Map("z"-> 3).withDefaultValue(Set())
val m4 = m3 ++ m2
m4("") // returns Set()

(m4 - "a")("") // returns Set()