how can you create such a DSL with

+

and

-

operators with implicit receiver?

branchFilter {
                +"refs/heads/my-feature"
            }

The key concepts are: • extension functions • operators can be extension functions • lambdas can be extension functions Now, all you have to do is create a

branchFilter

function that takes a parameter that is lambda with a receiver on some class (eg.

BranchFilterDSL

). Now, all functions declared in

BranchFilterDSL

(or as extensions of

BranchFilterDSL

) are available inside the lambda, and not outside of it.

yeah, but as far as I know, you can't use the

+

form unless you have an explicit receiver, ie

receiver + "refs"