An inauspicious start to my emacs trail 😞 - I had to edit the .emacs file and add variables of package archive sites.

trial not trail

@jeff-ster: that's not inauspicious, that's the first step

😄

now I get " CIDER's version (0.12.0) does not match cider-nrepl's version (nil). Things will break!"

Is that 'inauspicious'?

THIS is what emacs is known for. if you get my drift

Its the first step without telling you how to accomplish it.

Anyways I am on my way

@jeff-ster: I'm running into the same issue on OS-X lol.

you have to insert this in your project.clj :plugins [[cider/cider-nrepl "x0.12.0"]]

oops... no 'x'

That gets rid of the warning

hm. I'll give that a go.

I already had it added in ~/.lein/.profiles.clj, figured that should have done it.

@jeff-ster: that you think emacs is going to work is the inauspicious thing

gotta calibrate your expectations such that when it does work, you're pleasantly surprised

@jeff-ster: afaik latest cider injects dependencies for you if you're doing a cider-jack-in

anyway the #C099W16KZ channel would suit you

({:number 15, :name "Flowers"},{:number 16, :name "Books"}) Hi, guys! Which is the best way (Clojure way) to add 1000 to each number in this collection? I think that the solution that I have is a bit verbose... (map #(hash-map :number (+ 1000 (:number %)) :name (:name %)))

(map #(update % :number inc) ...)

@lucelios: (map #(update % :number (partial + 1000)) foo)

note: update was added in 1.7

use update-in if you’re using < 1.7

thanks a lot @conormcd @bostonaholic !!!

if you do a lot of nested operations like this, take a look at https://github.com/nathanmarz/specter

i’m curious if anyone is familiar with ring/compojure and middlewares — i’m wondering if it’s possible to write a proxy middleware?

@lwhorton: You could see how ring-proxy does it and go based of that: https://github.com/tailrecursion/ring-proxy/blob/master/src/tailrecursion/ring_proxy.clj

well, I was digging around in there and the problem I’m having is perhaps conceptual

when passing the merged http-opts to clj-http.client/request is that a blocking operation?

Hey guys. Just curious everytime I try to hit an https endpoint in my ring clojure application, I see the :ssl-client-cert field as nil even thought I have the ring service setup to handle https. (I can hit the https endpoint, but the client cert is always nil)

because it seems to me that there’s some issue with the sync/async nature — if I do a GET, it is successfully proxied, but the response is always 404.. even though logging after the request happens shows the correct proxy result.

almost like ring says “oh no immediate response i’m going to use a 404 middleware"

disregard that whole thing… I had a misplaced paren that was causing a bad if-let block to return too soon.

Does anyone have example of to do an https call using clj-http. I want to pass an actual client certificate and not just the :insecure option

john.carnell: https://github.com/dakrone/clj-http#keystores-trust-stores

Thanks for the pointer

https://github.com/dakrone/clj-http/blob/master/test/clj_http/test/conn_mgr_test.clj#L49

there's a test that exercises what you want, hope it serves as a good example

Thanks

what's the consensus on parinfer?

Personally, I much prefer parinfer.

I find paredit more than a little overbearing.

i'm a big fan of paredit. but i haven't looked too far into parinfer. I also really liked lispy, but haven't used it much recently as sometimes it gets into an invalid state with a mismatched paren

parinfer is just really new, and anyone who has spent time using paredit has had their brain so thoroughly warped by it that they usually aren't looking for anything else

there is actually some other emacs mode that is sort of like paredit, which I tried for about a day before my paredit addled mind rejected all the slight differences from paredit as wrong

i’m actually using atom text editor right now, not emacs

Actually, I had my brain so warped by paredit with Emacs that I was institutionalized in a Vim rehab facility. Gave up on using Emacs for Clojure (and lisp) until parinfer came along.

"usually"

non-emacs text editors are where there is a lot of new people picking up clojure, and many of them are javascript based, so parinfer drops in well, and if you are new to clojure you likely are not so accustomed to paredit that you don't want to use anything else

doesn't cursive default to using parinfer now instead of the port of paredit?

I started with Emacs and Common Lisp many, many years ago, long before Clojure came along. I got along fine with just parenthesis matching. Then people told me that I just had to start using this new paredit thing, and it was all downhill from there. On the other hand, parentheses were never my biggest issue in writing lisp-y code. I know some people just love it.

I use parinfer in vim and it’s fantastic

funny thing is, i used emacs up until around 2 years ago

but now i’m starting clojure, maybe i should look at emacs again

is emacs still the best when it comes to having a repl built-in?

vim does too, can’t speak to whether emacs’ support is better

I was using vim up until I got my first clojure job about six years ago, that job wanted everyone with a similar setup for the sake of pairing, and I cannot imagine switching back to vim

there are jobs where you HAVE TO use emacs? 😄

i can't imagine using an emacs mode on a lisp that didn't have some notion of structured editing, like slurp

My point with parinfer is basically, it is a new and interesting looking thing, but you'll find many (but not all) people who have been writing clojure for a long period of time (many using emacs) who are not all that interested, not because of anything problematic with parinfer, but because they have already made their peace with some other bit of tooling

when I used vim, I would use vim for writing code, but now I use emacs, I use it for so much stuff, I want to say everything even though it isn't really. at one time I had some patches that embedded a webkit view in an emacs buffer (and it sort of kind of worked). org-mode is amazing

a webkit view, that’s incredible

that sounds pretty cool

i think the biggest drawback of emacs is that it’s still centered solely around text

UIs have changed so much

what should it center on?

atom, by being a browser under the hood, and exposing js and css, can house some really powerful plugins that you could never implement in emacs

like what?

its crazy that you need a patch to bundle a half-working webkit view in a buffer

(asking as an occasional atom user looking for Cool Tips)

@amonks: look up activate-power-mode 😄 😂

ok yeah that’s totally nuts

wow

do you have a favorite case where that kind of ui control is used for something more useful?

I can imagine some possibilities

https://github.com/hiredman/emacs-mac-port/compare/master...webkit

activate-power-mode would be fun for livecoding

rendering your application in a buffer sounds good already, graphical tools for building UIs ala Netbeans for java etc.

custom buttons etc.

there’s a toolbar plugin for atom that i’m using too, it makes using proto-repl easier

I need help with writing a macros

I have a macro like this:

that displays an expression and its evaluation

(disp (map inc [1 2 3])) returns (map inc [1 2 3]) => (2 3 4)

no, the code you pasted isn't valid, it will throw an error when the reader tries to read it

I’ve fixed the code of the macro

I had a typo

now I want to be able to pass several expressions to my macro and to get the expressions and their evaluations one by one

the easiest way to do it, is to not use a macro

for me, (disp (map inc [1 2 3])) returns "(map inc [1 2 3]) => clojure.lang.LazySeq@7c42”

treat the expressions as data by making them quoted forms, and call eval on them when you want to see what they eval too

I don’t want to use eval

eval is exactly what you want

if you have a collection of forms, you can map eval over them

I know but I feel that macro is more elegant in this case

your feeling is wrong

why?

because eval exactly meets your requirements, and macros do not

if you use that macro, and don't treat forms as data, you can't even have a collection of forms

and even if you could, you couldn't use that macro to do what you want

what do u mean by treating form as data?

when you quote a form, you get the datastructure of the form, instead of the evaluated result

user=> (for [form ['(map inc (range 10)) '(map dec (range 10))]] [(pr-str form) (pr-str (eval form))])
(["(map inc (range 10))" "(1 2 3 4 5 6 7 8 9 10)"] ["(map dec (range 10))" "(-1 0 1 2 3 4 5 6 7 8)"])
user=> 

you could call it like this (disp ['(map inc [1 2 3]) '(map inc [3 2 1])])

I have modified my macro to use print instead of str like this

and now it returns the evaluated result instead of the datastructure of the form

why?

why print and str don’t behave in a similar way?

it doesn't do that

you may think you are seeing it do that, but that is an artifact of something else

e.g. maybe you have some function in which the macro is called and didn't realod the function after changing the macro

but that macro definitely doesn't return the evaluated result of anything

I’m testing in the REPL

then the macro you created isn't what you pasted

(macroexpand '(disp x)) will show you

yeah, so you said it returns the evaluated result, to me that means it returns the result of evaluating the form (talking about return values of macros is problematic for reasons), what did that mean to you?

in that repl I see it evaluating to a string of the form and the result of evaluating the form

to me, the form is (map inc [1 2 3]) and the evaluation is (2 3 4)

which is exactly what I wanted

yeah, and those are both in that string

which is exactly what I wanted

but with str I got

(map inc [1 2 3]) => clojure.lang.LazySeq@7c42

because the .toString on things isn't readable

if you want readable forms use the pr family of functions

(pr, prn, pr-str, etc)

ok

so again, why my macro -with pr-str - is wrong?

are you asking because it is doing something you don't want it to do? or are you asking for a general critique of the endeavor?

try mapping it over a collection of forms

(you won't be able to map a macro directly)

This is what I’m trying to do

But with no sucess

yeah, so don't use a macro

exactly

The problem with eval

is that I want my code to be portable and to run on clojurescript

and I don’t want to use self-host cljs for this case

clojurescript is self-hosted now, so it should have no problem eval'ing

yeah, you want it to run in a text area where people can type forms in to the browser and see the results, right?

Yeah

you cannot do that with a macro

macros only have data available during compilation to work with

you are talking about taking data from when the program is running

not really. I want to handle this kind of cases: (disp (map inc [1 2 3]) (map dec [4 5 6]))

but you want (map inc 1 2 3) to be something someone can type in to a text area in a webpage, right?

no

so where does (map inc [1 2 3]) come from?

The whole (disp (map inc [1 2 3]) (map dec [4 5 6])) is going to be typed by the user

you cannot do that without eval

that is straight up code to run, eval is what does that

like this: http://bit.ly/1pc440w

the definition of eval is basically: given a clojure expression, what is its value

yeah, klipse uses self hosted cljs to do that

if you have requirements, where any part is "given a clojure expression, get its value" that is eval

I know, I’m one of the authors of klipse

But I don’t want to use self-host inside the self-host code of klipse

I still cannot understand why I couldn’t be able to evaluate (disp (map inc [1 2 3]) (map dec [4 5 6]))

with a macro

as long as the expressions are always compile time constants you can

but that is basically never the case

if you want to have a text box a user can type a form in to, and evaluate it, that form isn't known at compile time, so a macro won't know what to do with it

I think that in my use case, it works

the proof is that with one expression everything works fine

I just can’t find the proper way to make it work for several expressions

;; hiredman ಠ_ಠ
(defmacro disp [& forms] (cons `list (for [form forms] ...))) 

trying...

I am able to get the form but not its evaluation

(disp (map inc [1 2 3]) (map dec [4 5 6])

=> ("form => (map inc [1 2 3])" "form => (map dec [4 5 6])”)

yes, that’s how it should work

you need (list 'quote form) not 'form

and, again, use the pr family, not str

looking at the macro expansion should be illuminating

Now I get ("(quote (map inc [1 2])) \" => \" (map inc [1 2])”)

macroexoand didn’t help

I cannot find the way to evaluate an expression inside a macro

;; hiredman ಠ_ಠ
(defmacro disp [& forms]
   (cons `list (for [form forms]  (str (pr-str (list 'quote form)) " => " (pr-str form)))))

@hiredman: it doesn’t work.

oh, duh, right

I should have just used syntax quote like darwin did

suppose I am writing a library to implement a protocol which is built on http. Are there good ways to allow my user to choose their own http client library? e.g. they may want to use clj-http or aleph or ...

(defmacro disp [& forms] (cons `list (for [form forms]  `(str (pr-str '~form) " => " (pr-str ~form)))))

thanks @hiredman and @darwin

;; something like this with the thing-that-does-http passed in on each request
(my-library/query #(http/post ""
               {:content-type %1
                :accept %2
                :body %3})
            "SELECT  ?p ?o WHERE { </foo/2> ?p ?o }")

@telent I would abstract calls into a http library with set of well-defined functions, and provide one default implementation for clj-http or what is your favourite one, this way you allow user to swap them for their own implementation

I pretty much don't use anything besides clj-http, what are libraries are you trying to support, and how closely do their models of http match?

aleph is an awful lot like clj-http (it says) but returns deferred objects that need dereffing

so not plug-compatible

actual swapping mechanism is not that important IMO, Clojure protocols would work, multimethods is also an option, or plain map would work as well

re: disp, generating literal calls to list can result in some oddess http://dev.clojure.org/jira/browse/CLJS-1617

a very dirty solution would be to declare the methods as ^:dynamic and let user swap them in the namespace

http-kit says "modelled after clj-http" but again i don't know how closely

so maybe just provide an async and a sync option built in to the library instead of arbitrary http client plugability

of course option (c) is Just Use clj-http because the chance in any production stack of it not being a dependency of something else the client already uses is tending to zero quite rapidy

protocols sound like they ought to be the "elegant" answer though

in one of my libraries, I simply keep pluggable methods in a config map, and provide one default imlementation:

https://github.com/binaryage/chromex/blob/master/src/lib/chromex/config.clj

If a library extends a protocol to Throwable, and I extend the same protocol to clojure.lang.ExceptionInfo, which implementation will win?

nm, I see that ties are broken by the class hierarchy

Anyone know a solid mqtt broker library?

Most that I find look to be abandoned