How do I make a macro that’s like the hash function? i.e. has an even number of expressions in the argument positions? Specifically, how do I match them as key value pairs in syntax parse?

For example, in the syntax documentation (meta programming helpers), the docs show how to re-implement let, but what if I wanted it to work without putting bindings in parens, like so: (mylet (a 1) (+ a 2)) The docs show this as an example that rightfully doesn’t work, but how do I make it so that it works like that?

As in, I want (mylet (a 1 b 2) (+ a b)) to work.

Never mind, the “Ellipsis-head Patterns” explains how.