Why does Eclipse show incomplete Scala classes in the Outline view?

Context: Scala project with imported library such as akka-http.

IDE: Eclipse (mars) + Scala-IDE 4.3

OS: Windows

I've configured sbt to download source code related to dependent projects, so I can view/inspect libraries more fully.

When I bring up akka.http.scaladsl.server.Directive I see only the first few members of that class in the Outline view. I can see additional members in the code that are not displayed in the Outline.

Why am I not seeing the full outline?

Solution

Short Answer

Right click on the project to open Properties -> Resource -> Text file encoding, and set to UTF-8.

This can also be set for the workspace properties; it's not clear to me if changing the workspace properties auto-sets existing projects, I'm guess it doesn't.

Why?

Admittedly a guess, but...

The problem seems to be associated with the combination of Scala IDE 4.3 (for Eclipse), Windows, and assumptions about source files and text encodings:

The Eclipse Scala-IDE 4.3 has a new Outline view, which seems to render a better representation of Scala classes by deferring to source. And it fails to do that properly when it doesn't grok the text encoding.
In Eclipse the default text file encoding is "Inherited from container" for the workspace. I presume existing projects inherit that setting from the workspace.
The Windows text file encoding (the container mentioned previously) is ISO-8859-1, or possibly something else... but not UTF-8.
In my problem Outline view, it turns out that the last member displayed for a class contains a unicode '⇒' (syntactically equivalent to '=>' in Scala).
silent boom