eevee

class WeakProperty:
    """Descriptor that automatically holds onto whatever it contains as a weak
    reference.  Reading this attribute will never raise `AttributeError`; if
    the reference is broken or missing, you'll just get `None`.

    The actual weak reference is stored in the object's `__dict__` under the
    given name, so this acts as sort of a transparent proxy that lets you
    forget you're dealing with weakrefs at all.

    Of course, if you try to assign a value that can't be weak referenced,

gvx

from collections import OrderedDict
from inspect import Parameter, signature
from itertools import chain, starmap
from operator import itemgetter

__all__ = ['namedtuple']

dict_property = property(lambda self: OrderedDict(zip(self._fields, self)),
                         doc='dictionary for instance variables (if defined)')

henrik

defmodule Lab do
  defmacro say({:when, _, [message, condition]}) do
    {result, _} = Code.eval_quoted(quote do
      case true do
        true when unquote(condition) -> true
        true -> false
      end
    end)

    if result do

andytill

Covering more with unit tests

Unit tests are quick to run, quick to write in bulk, target a small area of code, are not prone to timing issues and other intermittent failures and have excellent reporting tools.

However, actual usage is often prevented by side effects which require resources such as processes, ports and ets tables to exist or will crash the test.

Separating code into pure and impure functions can help and is typically beneficial. It can also harm readability, and even then not enable full coverage using unit testing. For example:

receive_message(Msg) ->

skippy

#cloud-config
---
coreos:
  units:
  - name: update-fleet-metadata.service
    command: start
    content: |-
      [Unit]
      Description=Update Fleet metadata tag
      Before=fleet.service

kcurtin

defmodule DBTransactions do
  use ExUnit.CaseTemplate

  setup_all do
    Ecto.Adapters.SQL.begin_test_transaction(Repo)

    on_exit fn ->
      Ecto.Adapters.SQL.rollback_test_transaction(Repo)
    end
  end

swannodette

(ns react-cljs.core
  (:require React))

(declare render)

(defn handle-change [e]
  (render {:text (.. e -target -value)}))

(defn render [{:keys [text]}]
  (React/renderComponent

henrik

defmodule Lab do
  defmacro say({:when, _, [message, condition]}) do
    {result, _} = Code.eval_quoted(condition)

    if result do
      quote do
        IO.puts unquote(message)
      end
    end
  end

martintrojer

;; ------------------------

(defn- log-time [{:keys [ns name line]} f & args]
  (let [start   (System/nanoTime)
        res     (apply f args)
        elapsed (quot (- (System/nanoTime) start) 1000)]
    (log/debug (format "%s/%s:%s %dus" ns name line elapsed))
    res))

(defn enable-timing [var]

alandipert

ClojureScript macros: kinda, sorta, not really.

ClojureScript does not have a standalone macro system. To write ClojureScript macros, one must write them in Clojure and then refer to them in ClojureScript code. This situation is workable, but at a minimum it forces one to keep ClojureScript code and the macros it invokes in separate files. I miss the locality of regular Clojure macros, so I wrote something called maptemplate that gives me back some of what I miss. The technique may be useful in other scenarios.

Problem

Suppose you're wrapping functionality in another namespace or package so that you can have your own namespace of identically named but otherwise decorated functions:

ClojureScript: