so nil? isn't an option?

@noisesmith nil? returns true for js/undefined

oh, tricky

Unfortunately, it leads to a difference with Clojure for

(def x)
(nil? x)

can you even (def x ) in Clojure?

oh nvm

it’ll be “unbound”, IIRC

right, it's a special placeholder class

clojure.lang.Var$Unbound - pretty much just exists to say something meaningful via its name in stack trace (and to check for equality to itself of course)

if I want to send emails via sendgrid (or any other mail service) I should still go through my own backend right?

otherwise I would have to put my key in the JS code

and related question, there seems to be many libraries to do HTTP calls in cljs

any suggestions on which one to use?

@andrea.crotti I’ve been using @r0man ‘s great https://github.com/r0man/cljs-http

As for your first question, you are correct.

ah cool @luchini , looks like it requires cljs spec alpha though

or maybe not might be an unrelated error sorry

So how do I use macros from clojurescript? If I have two files clj/a.clj and cljs/a.cljs both with namespace a. If I defmacro in a.cljs, the macro should be available in cljs/a.cljs, correct?

Hm... it only seems to work if I name the clj file differently

How would I define a macro m that does this:

(m ['a 'b]) => (fn [a b])

@urbank what about this?

@darwin Aha, right. But I need to be able to use the symbols in the body of the function. Is that even still in the scope of macros?

I'll be more specific about what exactly I want. Now perhaps a macro should not be used for this, but here goes:

@urbank this can be done by a macro, macros simply generate code your would want to write by hand

I just don’t follow why ‘foo and ‘bar have to be quoted, and why you even specify some names there, the generated function will not “expose” them outside

the way you wrote the examples, the macro will generate a code defining a lambda function for you, but names of parameters will be irrelevant at that point

@darwin But you have to tell the macro somehow how many arguments you want and where to put them in the get-in vector, right?

@darwin Right, that's good, but I don't know what to use to take an arbitrary vector amount of _s and make them correspond to arguments of a function, and then refer to them in the body of that function. If that makes sense. So p1# and p2# can't be referred to directly inside the macro because you don't know in advance the number of _s.

macro gets input code form as data and can do whatever it wants to generate a new form as data which will replace the macro “invocation” in-place - so you can use your clojure-fu to inspect input vector, process _ positions and generate code based on that

@darwin Heh, not sure what do say. Sounds obvious now that you say it. It is just clojure data structures after all. Thanks! 🙂

@urbank wait, will give you some start code you could tweak further

@urbank ^^

@darwin Cool. I'll delve into it tomorrow. Have to get some sleep now. Thanks very much 🙂

np, good night 🙂