> large parts of Gradle are actually implemented in Groovy
I thought it was just the plugin and DSL handling code. That would explain why Gradle's so slow, then.
> the DSL, which can be used purely declaratively, but it's not limited to such use
Virtually no-one uses Groovy procedurally, only declaratively, in Gradle build scripts, so although that's true in theory, in practise only the non-Turing Complete portions of Groovy are used. Calling it a programming language there is like calling HTML one because you can embed Javascript in HTML.
