mfikes

The following works in Clojure:

(keys (filter (comp odd? val) {:a 1 :b 2 :c 3}))

The docstrings for keys and vals don't indicate that you can do this. Is this accidential or intentional?

I vaguely recall Alex Miller indicating at some point that this capability was deemed useful and is intentionally allowed. Yes, this is an appeal to authority, but nevertheless, it makes a fairly convincing argument.

MichaelCurrin

Set up Jekyll environment on macOS

Set p Ruby, Bundler and a project-level Jekyll on macOS Catalina and up

This guide is for macOS Catalina and is based on the Jekyll on macOS doc and my experience.

1. Install dev tools

Use the XCode CLI to install dev tools. Recommended so that you can install native extensions when installing gems.

roman01la

(ns utils.re-frame
  (:require [cljs.compiler :as cljsc]))

(defn- anonymous-function-declaration? [form]
  (and (list? form)
       (= 'fn (first form))
       (vector? (second form))))

(defn- query-id->js-fn-name [query-id]
  (let [ns-part (when-let [ns-part (namespace query-id)]

spacegangster

;; UPD hey, I'm not sure now if those zones are correct throughout the year
;; see this https://www.creativedeletion.com/2015/01/28/falsehoods-programmers-date-time-zones.html
;; Sorry for misleading you
[{:option/value "Pacific/Tarawa"               :option/label "(GMT +12:00) Tarawa"}
 {:option/value "Pacific/Auckland"             :option/label "(GMT +12:00) New Zealand Time"}
 {:option/value "Pacific/Norfolk"              :option/label "(GMT +11:00) Norfolk Island (Austl.)"}
 {:option/value "Pacific/Noumea"               :option/label "(GMT +11:00) Noumea, New Caledonia"}
 {:option/value "Australia/Sydney"             :option/label "(GMT +10:00) Australian Eastern Time (Sydney)"}
 {:option/value "Australia/Queensland"         :option/label "(GMT +10:00) Australian Eastern Time (Queensland)"}
 {:option/value "Australia/Adelaide"           :option/label "(GMT +9:30) Australian Central Time (Adelaide)"}

roman01la

ClojureScript REPL Workflow

Short write up on using REPL when developing UIs in ClojureScript.

Hot-reload on save or Eval in REPL?

Everyone's standard approach to hot-reloading is to use a tool (Figwheel or shadow-cljs) that reloads changed namespaces automatically. This works really well: you change the code, the tool picks up changed files, compiles namespaces and dependants, notifies REPL client which then pulls in compiled changes, and re-runs a function that re-renders UI.

The other approach is to use ClojureScript's REPL directly and rely only on eval from the editor. This more or less matches Clojure style workflow. This approach might be useful when you don't want tools overhead or hot-reloading becomes slow for you or you just used to this style of interactions. Also changing code doesn't always mean that you want to reload all the changes. On the other hand it is very easy to change a couple of top-level forms and forget to eval one of them.

dosbol

Rich Already Answered That!

A list of commonly asked questions, design decisions, reasons why Clojure is the way it is as they were answered directly by Rich (even when from many years ago, those answers are pretty much valid today!). Feel free to point friends and colleagues here next time they ask (again). Answers are pasted verbatim (I've made small adjustments for readibility, but never changed a sentence) from mailing lists, articles, chats.

How to use:

• The link below in the summary jumps at the answer on this page.
• The link on the question itself points back at the original post.

Summary

freetonik

/* http://meyerweb.com/eric/tools/css/reset/ 
   v2.0 | 20110126
   License: none (public domain)
*/

html, body, div, span, applet, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
a, abbr, acronym, address, big, cite, code,
del, dfn, em, img, ins, kbd, q, s, samp,
small, strike, strong, sub, sup, tt, var,

reborg

Rich Already Answered That!

A list of commonly asked questions, design decisions, reasons why Clojure is the way it is as they were answered directly by Rich (even when from many years ago, those answers are pretty much valid today!). Feel free to point friends and colleagues here next time they ask (again). Answers are pasted verbatim (I've made small adjustments for readibility, but never changed a sentence) from mailing lists, articles, chats.

How to use:

• The link in the table of content jumps at the copy of the answer on this page.
• The link on the answer itself points back at the original post.

Table of Content

paultopia

(ns upload-file.core
  (:require [reagent.core :refer [render atom]]
            [cljs.core.async :refer [put! chan <! >!]])
  (:require-macros [cljs.core.async.macros :refer [go go-loop]]))

;; derived from https://mrmcc3.github.io/post/csv-with-clojurescript/
;; and based on reagent-frontend template. 

;; dependencies from project.clj in addition to clojure, clojurescript, and reagent:
;; [org.clojure/core.async "0.2.395"]

joepie91

Not all random values are created equal - for security-related code, you need a specific kind of random value.

A summary of this article, if you don't want to read the entire thing:

• Don't use Math.random(). There are extremely few cases where Math.random() is the right answer. Don't use it, unless you've read this entire article, and determined that it's necessary for your case.
• Don't use crypto.getRandomBytes directly. While it's a CSPRNG, it's easy to bias the result when 'transforming' it, such that the output becomes more predictable.
• If you want to generate random tokens or API keys: Use uuid, specifically the uuid.v4() method. Avoid node-uuid - it's not the same package, and doesn't produce reliably secure random values.
• If you want to generate random numbers in a range: Use random-number-csprng.

You should seriously consider reading the entire article, though - it's