olivergeorge

Looking at some old code there were a couple of undesirable features. One particular code smell is a good motiviating example: handlers calling other handlers.

It encourages the developer to "register handlers as reusable components" but that's a pretty clumsy way to write utilties. Over time those util handlers were collecting barnicles and were becoming very hard to reason about or refactor.

Handlers, actions and utils

With the advent of :fx we have a clean composable alternative with some desirables traits.

My app has three namespaces (app.handlers, app.actions and app.utils)

ryan-haskell

module Components.Carousel exposing
    ( Carousel
    , create
    , next
    , previous
    , select
    , view
    )

import Array

divs1210

(defn extrapolate
  "Returns a lazy seq produced by extrapolating `coll` with given rules.
  On each iteration,
    `gen-next` is called with the entire seq generated till this iteration
    `shrink` is called with the extrapolated seq (`identity` by default)"
  ([gen-next coll]
   (extrapolate gen-next identity coll))
  ([gen-next shrink coll]
   (concat coll
           (let [curr (volatile! (seq coll))]

mitranim

(defmacro return-or [sym expr] {:pre [(symbol? sym)]}
  `(if (reduced? ~sym) (unreduced ~sym) ~expr))

(defn imp-block [[expr & tail-exprs]]
  (match expr

    (('let pattern init) :seq)
    (if-not tail-exprs
      (list init)
      (match (imp-block tail-exprs)

garretfick

# This terraform configuration generates a Heroku PHP application
# using the Heroku postgress database addon and creates an AWS S3
# bucket to host static files for the application.
# The site is sufficiently simple that this configuation is
# contained in a single file
# The build creates environment variables in the Heroku application
# containing the credentials for the S3 bucket.

# Authentication for the AWS provider - we use this access
# key in order to be able to create a new AWS user and the S3

mathieuancelin

package bar.foo.lenses;

import java.util.function.BiFunction;
import java.util.function.Function;

public class Lens<A, B> {

    private final Function<A, B> getter;
    private final BiFunction<A, B, A> setter;

semperos

;; Big thanks to Christophe Grand - https://groups.google.com/d/msg/clojure/L1GiqSyQVVg/m-WJogaqU8sJ
(defn scaffold [iface]
  (doseq [[iface methods] (->> iface .getMethods 
                            (map #(vector (.getName (.getDeclaringClass %)) 
                                    (symbol (.getName %))
                                    (count (.getParameterTypes %))))
                            (group-by first))]
    (println (str "  " iface))
    (doseq [[_ name argcount] methods]
      (println 

pal

package com.palbrattberg.classpathtools;

import java.io.File;
import java.io.FilenameFilter;
import java.io.Serializable;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Enumeration;