ckirkendall

(use '[clojure.core.match :only [match]])

(defn evaluate [env [sym x y]]
  (match [sym]
    ['Number]   x
    ['Add]      (+ (evaluate env x) (evaluate env y))
    ['Multiply] (* (evaluate env x) (evaluate env y))
    ['Variable] (env x)))
    
(def environment {"a" 3, "b" 4, "c" 5})

korya

Source: http://willandorla.com/will/2011/01/convert-folder-into-git-submodule/

1. Clone new repository

$ git clone --no-hardlinks original-repo copied-repo

2. Filter out the files you want to keep and remove the others

wolever

-- Functions to create and draw histograms with PostgreSQL.
--
-- psql# WITH email_lengths AS (
--    -#    SELECT length(email) AS length
--    -#    FROM auth_user
--    -#    LIMIT 100
--    -# )
--    -# SELECT * FROM show_histogram((SELECT histogram(length, 0, 32, 6) FROM email_lengths))
--  bucket |                range                | count |              bar               |             cumbar             | cumsum |         cumpct         
-- --------+-------------------------------------+-------+--------------------------------+--------------------------------+--------+------------------------

soarez

How to setup your own CA with OpenSSL

For educational reasons I've decided to create my own CA. Here is what I learned.

First things first

Lets get some context first.

cdipaolo

// haversin(θ) function
func hsin(theta float64) float64 {
	return math.Pow(math.Sin(theta/2), 2)
}

// Distance function returns the distance (in meters) between two points of
//     a given longitude and latitude relatively accurately (using a spherical
//     approximation of the Earth) through the Haversin Distance Formula for
//     great arc distance on a sphere with accuracy for small distances
//

nesquena

/*
  Source: http://www.littlerobots.nl/blog/Handle-Android-RecyclerView-Clicks/
  USAGE:
   
  ItemClickSupport.addTo(mRecyclerView).setOnItemClickListener(new ItemClickSupport.OnItemClickListener() {
      @Override
      public void onItemClicked(RecyclerView recyclerView, int position, View v) {
          // do it
      }
  });

bastman

Docker - How to cleanup (unused) resources

Once in a while, you may need to cleanup resources (containers, volumes, images, networks) ...

delete volumes

// see: https://github.com/chadoe/docker-cleanup-volumes

$ docker volume rm $(docker volume ls -qf dangling=true)

$ docker volume ls -qf dangling=true | xargs -r docker volume rm

jaredsburrows

import rx.Observable;
import rx.subjects.PublishSubject;
import rx.subjects.SerializedSubject;
import rx.subjects.Subject;

/**
 * @author <a href="mailto:jaredsburrows@gmail.com">Jared Burrows</a>
 */
public final class RxBus {
    private final Subject<Object, Object> bus = new SerializedSubject<>(PublishSubject.create());

benediktg

(based on these two blog entries and inspired by Fedora-Blog)

First install pam_kwallet:

sudo zypper in pam_kwallet

Then edit the files /etc/pam.d/passwd, /etc/pam.d/login and /etc/pam.d/sddm as follows, i.e. add the lines beginning with a - (the hyphens are valid PAM syntax to reduce log entries if these PAM modules should not exist) and ending with the ### comment:

/etc/pam.d/passwd :

posener

Why I Recommend to Avoid Using the go-kit Library

There is a trending 'microservice' library called go-kit. I've been using the go-kit library for a while now. The library provide a lot of convenience integrations that you might need in your service: with service discovery with Consul, distributed tracing with Zipkin, for example, and nice logic utilities such as round robin client side load balancing, and circuit breaking. It is also providing a way to implement communication layer, with support of RPC and REST.