cespare

def callback(message):
  print(message)

foo = ["a", "b", "c"]

# Environment variables are only captured as references by the lambda:
bar = [lambda: callback(s) for s in foo]
for f in bar:
  f() # => c x 3

cespare

var Foo;
var __bind = function(fn, me){ return function(){ return fn.apply(me, arguments); }; };
Foo = (function() {
  function Foo() {}
  Foo.prototype.init = function() {
    var lalala = this;
    $("#submitButton").click(__bind(function(event) {
      // throws an error "HTMLDocument element does not have property onSubmitButtonClicked
      return this.onSubmitButtonClicked(event);
    }, lalala));

cespare

import scala.collection.mutable.Map
import scala.collection.mutable.Buffer

val foo = Map[Int, Buffer[Int]]() withDefault ((key) => Buffer())

foo(1) = Buffer(1, 2)
foo(1) += 3
foo(1) // => ArrayBuffer(1, 2, 3)
/* This all seems as expected */

cespare

foo = (f1, f2) ->
  f1()
  f2()

# Doesn't work -- syntax error
# foo(-> console.log("hi from f1"), -> console.log("hi from f2"))

# Simplest way I've found to do it -- newlines added for clarity
foo(
  (-> console.log("hi from f1")),

cespare

# In your app

get "/whatever"
  erb :_partial_collection, :layout => false, :locals => { partials => partials } # partials is an array of other partials...
end

# in views/_partial_collection.erb

<% partials.each { |partial| %><%= erb partial, :layout => false %><% } %>

cespare

[
  ["/foo", "localhost:8090"],
  ["/bar", "google.com:80"],
  ["/", "localhost:3000"]
]

cespare

# Need to install imagemagick first.
# sudo apt-get install libmagickwand on ubuntu.
# Available on homebrew as well.

require "RMagick"

images = Dir["./*.png"]

start_time = Time.now

cespare

This is a very simple benchmark comparing the response times of a few different webservers for an extremely simple response: just reply with a snippet of static json. It came up in discussion of a real-life service: in the actual server, a long-running thread/process periodically updates the state from a database, but requests will be served with the data directly from memory. It is imperative, though, that the latencies be extremely low for this service.

This comparison was partly inspired by this blog post.

Method

cespare

package main

// #cgo CFLAGS: -I/usr/include/python2.7
// #cgo LDFLAGS: -lpython2.7
// #include <Python.h>
// int pyRunString(const char *s) { return PyRun_SimpleString(s); }
import "C"

import "unsafe"

cespare

type ApacheLogRecord struct {
	http.ResponseWriter

	ip                    string
	time                  time.Time
	method, uri, protocol string
	status                int
	responseBytes         int64
	elapsedTime           time.Duration
}