When it comes to iterating through sequences, why is there a first or rest but not an all?

What use would there be for an all that wouldn't be served just by the sequence itself, or a map, or something?

I think I’m having difficulty understanding how to apply certain data types, or extract certain data from a JSON rest response.

In Ruby I’d have used anarray.each combined with an if to filter some data

Can you show a concrete example? My guess is that it's probably something that can be handled with a simple map

move to #C1CGD283U

?

Poking around in there now

@dmbennett: serves me right for naming something tmp.

@dmbennett: the equivalent or ruby's Array#each would be doseq, i.e. loop through a sequence for side effects

Ruby

[1 2 3].each do |i|
  puts i
end

Clojure

(doseq [i [1 2 3]]
  (println i))

but depending on what you're trying to do there might be better ways. You should get familiar with doseq, map, for, doall, dotimes, loop

When you don’t need a reference to “moving element”, you can also use run!

(run! println [1 2 3])

Clojure Boot/HttpKit newbie question: Given this basic sample app running via Boot:

(ns geo.main
  (:require [org.httpkit.server :refer [run-server]]
            [geo.handler :refer [app]])
  (:gen-class))

(defn -main [& args]
  (run-server app {:port 8080}))

Moreover, the code works fine and the webserver correctly returns when run-server is called via the repl.

@dp take a look at https://github.com/pandeiro/boot-http

can someone enlighten me this particular cljs code?

(defn jsonp
  ([uri] (jsonp (chan) uri))
  ([c uri]
   (let [gjsonp (Jsonp. (Uri. uri))]
     (.send gjsonp nil #(put! c %))
     c)))

It is sending nil to the uri and when it gets a response, it put!s that response onto the channel.

so what's the difference between record instantiation in Clojure:

`(defrecord Planet [name moons volume mass]) => user.Planet (def earth (Planet. "Earth" 1 1.08e12 5.9e24)) => #'user/earth (def earth-> (->Planet "Earth" 1 1.08e12 5.9e24)) => #'user/earth-> (= earth earth->) => true`

Planet. vs ->Planet above

when one would want to prefer one over the other?

I prefer the second one. To use the first one in a different ns you will need to “import” the class, while the second one you can just “require” the ns

The first is using Java Interop, the second is the constructor defrecord generates for you. There is also map->Planet as well generated by defrecord.