As a debugger, GammaRay needs an ability to not only query runtime values but also execute arbitrary expressions in the context of a debugged program. In QML the concept of engines and contexts makes it easy to run scripts as if they were literally coded there in a *.qml file.

Of course, such feature would deserve its own tab in GammaRay UI, it would need history support, syntax highlighting and pretty-printing of resulting values. In other words, your typical REPL.