Juntao Qiu abruzzi

Hey! I saw this has been indexed by the search engines. It is a first draft of a post I ended up publishing on my blog at: Scaling PostgreSQL With Pgpool and PgBouncer

Thanks for stopping by!

PostgreSQL and Pgpool Architecture

There are a bunch of reasons why this is convoluted, mostly in building the URL to make the request:

You have to rely on an AJAX request, this example uses jQuery
To make a GetFeatureInfo request, you must provide a BBOX for a image, and the pixel coordinates for the part of the image that you want info from. A couple of squirrely lines of Leaflet code can give you that.
Output formats. The info_format parameter in the request. We don't know a priori which will be supported by a WMS that we might make a request to. See Geoserver's docs for what formats are available from Geoserver. That won't be the same from WMS to WMS, however.
WMS services return XML docs when there's a mistake in the request or in processing. This sends an HTTP 200, which jQuery doesn't think is an error.

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

So you're curious in learning this new thing called Reactive Programming, particularly its variant comprising of Rx, Bacon.js, RAC, and others.

Learning it is hard, even harder by the lack of good material. When I started, I tried looking for tutorials. I found only a handful of practical guides, but they just scratched the surface and never tackled the challenge of building the whole architecture around it. Library documentations often don't help when you're trying to understand some function. I mean, honestly, look at this:

Rx.Observable.prototype.flatMapLatest(selector, [thisArg])

Projects each element of an observable sequence into a new sequence of observable sequences by incorporating the element's index and then transforms an observable sequence of observable sequences into an observable sequence producing values only from the most recent observable sequence.

Reader Macros in Common Lisp

This post also appears on lisper.in.

Reader macros are perhaps not as famous as ordinary macros. While macros are a great way to create your own DSL, reader macros provide even greater flexibility by allowing you to create entirely new syntax on top of Lisp.

Paul Graham explains them very well in [On Lisp][] (Chapter 17, Read-Macros):

The three big moments in a Lisp expression's life are read-time, compile-time, and runtime. Functions are in control at runtime. Macros give us a chance to perform transformations on programs at compile-time. ...read-macros... do their work at read-time.

	//Thanks to https://github.com/stephanenicolas/Quality-Tools-for-Android/blob/master/build.gradle

	buildscript {
	repositories {
	mavenCentral()
	}
	dependencies {
	classpath 'com.android.tools.build:gradle:0.7.+'
	}
	}

	var gulp = require('gulp');
	var sourcemaps = require('gulp-sourcemaps');
	var source = require('vinyl-source-stream');
	var buffer = require('vinyl-buffer');
	var browserify = require('browserify');
	var watchify = require('watchify');
	var babel = require('babelify');

	function compile(watch) {
	var bundler = watchify(browserify('./src/index.js', { debug: true }).transform(babel));

	<html>
	<head>
	<link rel="stylesheet" href="/examples/stylesheets/ui-lightness/jquery-ui-1.8.16.custom.css" type="css">
	<script type="text/javascript" src="/examples/javascripts/jquery.min.js"></script>
	<script type="text/javascript" src="/examples/javascripts/jquery.base64.min.js"></script>
	<script type="text/javascript" src="/examples/javascripts/jquery-ui-1.8.16.custom.min.js"></script>
	<script type="text/javascript" src="/examples/javascripts/jquery.tmpl.min.js"></script>
	</head>

	<body>

	var mapStaff = function() {
	var values = {
	department: this.department,
	grade: this.grade,
	role: this.role,
	gender: this.gender,
	preferredName: this.preferredName,
	loginName: this.loginName,
	hireDate: this.hireDate,
	totalExperience: this.totalExperience,

	(defpackage :com.liutos.del0-interp
	(:use :cl)
	(:nicknames :del0-interp
	:interp))

	(in-package :interp)

	(defvar env0 '())

	(defun ext-env (x v env)

	@mixin ie6 { * html & { @content } }

	#logo {
	background-image: url("/images/logo.png");
	@include ie6 { background-image: url("/images/logo.gif"); }
	}