On Notation

*Note from the Editor:  Links and content of this post has been revisited December 2013. The original cite has been outdated. However you might find the content still valuable if you are, say a Javascript coder with some Java OOP backend.

String Concatenation in Flash, clearly explained by Mr. Francis Cheng from Adobe.

An excerpt:

To understand this issue, we need to see the expression from the compiler's point of view. To the compiler, the expression: 

"Hello" + + " world"is actually the following: 

"Hello" + ( + " world") 

So the short answer for those of you familiar with operator precedence rules is that the compiler first evaluates the expression (+ " world"), which yields NaN. 

The compiler then evaluates the expression "Hello" + NaN, which yields "HelloNaN". The reason for the compiler error is that in Strict Mode, ActionScript 3.0 does not allow the application of the the unary "+" operator to a value of type String. 

You'll get "HelloNaN" as the result if you turn off Strict Mode. If this makes little or no sense to you, read on for a more detailed explanation.

This post links to an excerpt of an article written in spanish by Dr. Vicenç Navarro.

I mention here in this, your, blog, because it bring some light on ethic values.

.....Me parece propio de un enorme relativismo ético poner todas las fuerzas y agentes políticos y sociales que intervinieron en aquellos conflictos bajo el mismo prisma valorativo negando que haya causas justas y causas injustas. Negar que las fuerzas aliadas que vencieron al nazismo en Europa durante la II Guerra Mundial luchaban en una causa justa en contra de una causa injusta –el nazismo- es negar la existencia de una estructura valorativa universal basada en el respeto a unos derechos humanos. Ni que decir tiene que los aliados cometieron también horribles atropellos de aquellos derechos. Pero estas atrocidades (que deben denunciarse) no negaron la justicia de su causa, lo cual no justificó tales atrocidades pero tampoco niega la validez de su causa...

And continues:
...... como lo atestigua que la victoria del lado golpista inició una dictadura enormemente brutal (por cada asesinato político que hizo Musolini, Franco hizo diez mil), asesinando a casi 200.000 personas en sólo el periodo 1939- 1945, y estableciendo un régimen totalitario que causó un gran subdesarrollo económico, social y cultural del país. Cuando el golpe militar ocurrió en el año 1936, el PIB per cápita español era semejante al italiano.
En 1975 cuando el dictador murió, el PIB per capita español era sólo el 64% del italiano y el 68% de los adultos en España tenía menos de seis años de educación.

Read the article here

Wanna ever program in Python? Android is you platform, dedicated to mobiles and provided by Google Inc.

Love that cab4me, mainly because of I hate to wait for a cab. Specially when it rains.

cab4me uses the location awareness of Android (GPS and cell-based), to make it easy for the user to order a cab to his current location without the need to know the exact address or to know the name of the cab company.

Coda of my favourite and a live-without everyday use app for MAC OS X, has been free upgraded.

You might need Coda to work in a comfortable way with your scripts, your style-sheets or your client's web-pages. Features in this update are numerous, but I point you over this ones:

• Custom books are searchable if you provide a relevant search URL
• Improved syntax coloring, including accurate coloring and completion when one language is nested in another (such as JavaScript and CSS within HTML)
• Subversion
• Javascript console
• Dragging a remote image file into an editor now generates a CSS style reference instead of HTML style if within a CSS context

And tones more. Thank you, team at Panic.

See the new releases here.

Google must win the handset operating system wars because Android’s true mission is to deliver ads, just as a magazine and its articles generally exist to deliver ads.

Read the complete article at B.Net

I always was certain that, opposed to the common opinion, rays 'came from earth' to sky and not inverse. From the basement to the top.

The video enlights in a way that my conceptions were not wrong at all ...in a way.

This is: Rays, as you may see in the video 'climb' from earth to clouds, even the initial reaction happens above. Comments are welcome, if you think I am wrong.


In Benjamin Franklin word's:

When rain has wet the kite twine so that it can conduct the electric fire freely, you will find it streams out plentifully from the key at the approach of your knuckle, and with this key a phial, or Leiden jar, maybe charged: and from electric fire thus obtained spirits may be kindled, and all other electric experiments [may be] performed which are usually done by the help of a rubber glass globe or tube; and therefore the sameness of the electrical matter with that of lightening completely demonstrated

In the type theory of PM, the class φ has the same logical type as the function φ. 
This makes it appropriate to use the following contextual definition, which allows one to eliminate the class term ψ from occurrences in the context f :

f {(ψ)} . = : (∃φ) : φ!x . ≡x . ψx : f {φ!} Df

or in modern notation:

f {z | ψz} =df ∃φ[∀x(φx ≡ ψx) & f (λx φx)], where φ is a predicative function of x

Scripting language, a semantic world where classes were replaced by functions.

Via The Notation in Principia Mathematica.

A clear and concise article on Intuitionism, a classical debate on truth and local truth appliable to computer programming, and more closely to game programming.

An excerpt:

Imagine a planet and a meteorologist at each point of the surface, measuring the local temperature T. We assume that T varies continuously with position. A statement such as T>273 is true at some points of the planet and false at others. We say that it is locally true at x if there exists a small neighborhood around x where it is true. In other words, a statement is locally, or stably true at a given point if it remains true when we perturb the point a little.

On this planet a statement is globally true if it is locally true everywhere, and it is globally false if its negation is locally true everywhere. There are also many intermediate levels of truth. The truth value (a measure of truth) of a statement is the set of those points at which the statement is locally true. Such a set is always open.


Worth two reads.