Remove redundant braces in with

[gilch]

from this

(with [[arg (expr)] [(expr)]] block)

to this

(with [(expr) :as arg
       (expr)]
  block)

[algernon]

I wouldn't use keywords there... instead:

(with [arg (expr)
       _ (expr)]
  block)

Just make them pairs - easy to split, easy to work with, less to type, and - in my opinion - feels more natural.

[gilch]

@algernon I like this suggestion. I had actually considered it before settling on the :as proposal, partially for consistency with import.

The _ isn't a good choice though. I know it's commonly used as a dummy variable in other languages. In Prolog and Lua, for example. It's not such a good choice in Python, however. In the Python shell, _ is like * in the Common Lisp repl or *1 in Clojure's repl. It's the value of the last input.

How about this instead:

(with [arg (expr)
       nil (expr)]
  block)

Rather than insert junk into the AST because Hy requires a variable we're not going to use, (be it _ or otherwise), the nil will make it clear that no assignment is being made. Since obviously you can't assign to nil. It's a literal. This may lengthen the implementation just a little bit, but it's not hard to check a list for nils.

[algernon]

Nil's fine, yep.

[algernon]

FWIW, this should be done after #713.