tatut

% clj -Sdeps "{:deps {juxt/crux-core {:mvn/version \"21.06-1.17.1-beta\"}}}"
Clojure 1.10.1

;; Require API and create noe
user=> (require '[crux.api :as crux])
nil
user=> (def crux (crux/start-node {})) ; start in-memory node
#'user/crux

;; Insert and query some data

hagmonk

Benchmarking Leiningen on Apple Silicon

Gene was tweeting about Clojure's startup performance on Apple Silicon, so I decided to benchmark my new MacBook Air with the M1 chip against my Intel based MacBook Pro.

TL;DR

The M1 chip in the MacBook Air - which lacks a fan - was able to quite tidily beat an almost top-of-the-line Intel chip.

samebchase

Parsing Clojure namespace forms using Raku grammars

One day, I started wondering if it would be possible to parse Clojure namespace forms and generate a dependency graph of the various namespaces used in a real-world Clojure project. While that was the original motivation, I ended up down the Raku grammar rabbit hole, and had an enjoyable time learning how to use them. I'm glad you're joining me in reliving that journey.

Background

ursuad

Kafka Topics

List existing topics

bin/kafka-topics.sh --zookeeper localhost:2181 --list

Describe a topic

bin/kafka-topics.sh --zookeeper localhost:2181 --describe --topic mytopic

Purge a topic

bin/kafka-topics.sh --zookeeper localhost:2181 --alter --topic mytopic --config retention.ms=1000

... wait a minute ...

ghoseb

(ns clj-spec-playground
  (:require [clojure.string :as str]
            [clojure.spec :as s]
            [clojure.test.check.generators :as gen]))

;;; examples of clojure.spec being used like a gradual/dependently typed system.

(defn make-user
  "Create a map of inputs after splitting name."
  ([name email]

dropmeaword

Browser histories

Unless you are using Safari on OSX, most browsers will have some kind of free plugin that you can use to export the browser's history. So that's probably the easiest way. The harder way, which seems to be what Safari wants is a bit more hacky but it will also work for other browsers. Turns out that most of them, including Safari, have their history saved in some kind of sqlite database file somewhere in your home directory.

The OSX Finder cheats a little bit and doesn't show us all the files that actually exist on our drive. It tries to protect us from ourselves by hiding some system and application-specific files. You can work around this by either using the terminal (my preferred method) or by using the Cmd+Shft+G in Finder.

Once you locate the file containing the browser's history, copy it to make a backup just in case we screw up.

kapilreddy

;; project.clj
;; [clj-time "0.6.0"]
;; [org.clojure/data.json "0.2.4"]
;; [clj-kafka "0.2.8-0.8.1.1"]

;; Utility to find offsets in a given Kafka topic for a given
;; cursor/point in time. The code assumes that each message has a
;; monotonically increasing number (ex. unix timestamp) associated with
;; it.

haridsv

What exactly is "iowait"?

To summarize it in one sentence, 'iowait' is the percentage
of time the CPU is idle AND there is at least one I/O
in progress.

Each CPU can be in one of four states: user, sys, idle, iowait.
Performance tools such as vmstat, iostat, sar, etc. print
out these four states as a percentage.  The sar tool can
print out the states on a per CPU basis (-P flag) but most

gfredericks

(defn with-local-redefs-fn
  [a-var its-new-value func]
  (cast clojure.lang.IFn @a-var)
  (alter-meta! a-var
               (fn [m]
                 (if (::scope-count m)
                   (update-in m [::scope-count] inc)
                   (assoc m
                     ::scope-count 1
                     ::thread-local-var (doto (clojure.lang.Var/create @a-var)

kristianhellquist

(defun copy-current-line-position-to-clipboard ()
  "Copy current line in file to clipboard as '</path/to/file>:<line-number>'"
  (interactive)
  (let ((path-with-line-number
         (concat (buffer-file-name) ":" (number-to-string (line-number-at-pos)))))
    (x-select-text path-with-line-number)
    (message (concat path-with-line-number " copied to clipboard"))))

(define-key global-map (kbd "M-l") 'copy-current-line-position-to-clipboard)