OK I've filed this here:
http://dev.clojure.org/jira/browse/ASYNC-79
In trying to create a minimal test case I tried a trivial macro
(defmacro my-case [expr cases] `(case ~expr ~@cases))
inside a go block, and that worked fine, so it's more subtle than just case in
a macro is broken.
I
Honestly, I'm against having core.async as anything other than a normal
macro. The less built-in magic the better, plus its nice to know that
almost everything I use, I could in theory build myself without hacking the
language itself, should I ever want to. The more features that get special
*I meant to write clean architecture :-)
On 23 July 2014 15:29, Daniel Kersten dkers...@gmail.com wrote:
Honestly, I'm against having core.async as anything other than a normal
macro. The less built-in magic the better, plus its nice to know that
almost everything I use, I could in theory
Thanks for your reply. That's pretty much what I'd come to understand. I'm a
bit puzzled why this restriction exists though. Of course function calls can't
be resolved at macro expansion time, so it makes sense that ! ! inside
functions can't be found. But I don't understand why the go macro
There's really two questions in there as I see it.
1. Why doesn't the go macro expand all nested macros.
2. Why can't the go macro find the ! and ! anyway
I don't know the answer to either, unfortunately.
Because macro expansion happens in reverse order to normal evaluation,
nested macros aren't
Not sure if I understood the initial question correctly, but isn't the
following sort of what you wanted?
;; ==
(require '[clojure.core.async :as async])
(defmacro dispatch-on [ch cases]
(let [argssym (gensym args__)
keysym (gensym key__)
ressym (gensym res__)
I tried it in ClojureScript and I did get the same error as your did. I believe
this is because the go-macro doesn't handle the case-statement correctly (or,
rather, not at all). Switching from (case key ...) to (condp = key ...) however
appears to do the trick (along with all the other awkward
Hi All,
I had a terrible time trying to write a convenience macro for reading from a
core.async channel.
The idea was to make it easier to do the common dispatch on first part of a
message pattern, as in:
(let [[msg args] (! my-channel)]
(case msg
:msg1 (let [[a b] args]
