Why does one select Scala type members with a hash instead of a dot?

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Example#Foo is called a type projection and will match any type Foo of any enclosing instance of type Example. If you write a type Example.Foo, the compiler will look for the value (and not type) called Example and will refer to its enclosing Foo type only. This is often used in the context of singleton objects.

For instance:

object MyEnum extends Enumeration {
  val EnumValue = Value
}

val e: MyEnum.Value = MyEnum.EnumValue

If Scala used . for type projections, this would lead to confusion because the preceding identifier could be interpreted either as a type or as a value… Hence the #. Note that, as @kassens writes, Java only has type projections in that respect.

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