Sobre a provinha do Google Developer Day 2011
Ano passado, quando a Google abriu as inscrições para o GDD, eu escrevi o primeiro de uma série de três artigos sobre a tal provinha. Esperei até o final das inscrições (e o sinal verde de um amigo que trabalha lá) para publicá-lo.
Não vou fazer diferente esse ano. Se você veio aqui querendo ver a solução dos problemas do ano passado, eles estão relacionados abaixo. Se, por outro lado, chegou aqui procurando um jeito fácil de entrar no evento, devia ter vergonha. Eu respeito a decisão da Google de usar a prova como uma forma de garantir que a platéia tenha melhores chances de entender o que o palestrante vai falar e não vou ajudar a estragar o processo de seleção de convidados deles. Quando as inscrições estiverem encerradas, eu volto aqui e publico a minha solução e aí você pode comparar com a sua.
De resto, boa sorte. A prova não é difícil e eu tenho certeza que você consegue. Você já chegou até aqui, afinal.
Um abraço e até lá.
Nota: Se você colocar aqui um comentário mostrando uma solução antes que sejam fechadas as inscrições, eu vou apagar pela mesma razão que me fez não publicar a minha ainda. Se você tem uma solução, volte depois.
Outra nota: Agora, que as inscrições estão encerradas, você pode achar soluções procurando no Google. Uma delas (em Java) foi postada em um comentário aqui. A mihha em Python está aqui. Há outras, algumas com escolhas de linguagem ainda mais estranhas do que a minha versão para computadores de 8-bits do ano passado. Acho uma pena que tantos tenham praticado GDD (Google-Driven Development, pun intended) e tenham googlado por respostas em vez de aprender a programar.
Emacs perfection - selecting fonts according to screen size
Most of the time, I work at my desk, where my netbook is hooked up to a reasonably sized monitor (the largest its feeble GPU can handle with acceleration). Since screen real-estate in that situation is abundant, I opted to use a larger font (one I made from the x3270 bitmap font, but that's another, much longer story). Unfortunately, when I am not at my desk, the 1024x600 LCD is quite limiting and the default options don't work for me. When I am away from the big screen monitor, screen real-estate is limited and a small font should be selected by default.
I started from the options the Custom menu gave me. Removing comments, it's a very simple snippet:
(custom-set-faces
'(default ((t (:inherit nil :stipple nil :inverse-video nil :box nil :strike-through nil :overline nil
:underline nil :slant normal :weight normal :height 140 :width normal :family "IBM 3270"))))
'(linum ((t (:inherit default :foreground "#777" :height 110)))))
Translating that to English, I have a font called "IBM 3270" at a 14-point height, with line numbers with 11 points. Very readable.
But that doesn't solve the problem when I am on the road.
The friendly guys at Stack Overflow pointed out one way to do it: x-display-pixel-width and x-display-pixel-height.
With that in hand, I can do:
(if (> (x-display-pixel-width) 1280)
; screen is big
(custom-set-faces
'(default ((t (:inherit nil :stipple nil :inverse-video nil :box nil :strike-through nil :overline nil
:underline nil :slant normal :weight normal :height 140 :width normal :family "IBM 3270"))))
'(linum ((t (:inherit default :foreground "#777" :height 110)))))
; screen is small
(custom-set-faces
'(default ((t (:inherit nil :stipple nil :inverse-video nil :box nil :strike-through nil :overline nil
:underline nil :slant normal :weight normal :height 110 :width normal :family "IBM 3270"))))
'(linum ((t (:inherit default :foreground "#777" :height 80)))))
)
and I can be happy.
But can I?
When I start Emacs without X (as in from a remote terminal), these functions issue an ugly warning telling me that X is not available and that I should --debug-init and fix the problem. That's safely ignorable (as these adjustments are being done when everything non-cosmetic is already in place, at least in my init.el), but, still, annoying.
There is a variable, window-system, that can help - it holds "x" if we are under the X windowing system and nil if we are using a character terminal. With it, I can do:
(if (and (eq 'x window-system) (> (x-display-pixel-width) 1280))
; screen is big
(custom-set-faces
'(default ((t (:inherit nil :stipple nil :inverse-video nil :box nil :strike-through nil :overline nil
:underline nil :slant normal :weight normal :height 140 :width normal :family "IBM 3270"))))
'(linum ((t (:inherit default :foreground "#777" :height 110)))))
; screen is small
(custom-set-faces
'(default ((t (:inherit nil :stipple nil :inverse-video nil :box nil :strike-through nil :overline nil
:underline nil :slant normal :weight normal :height 110 :width normal :family "IBM 3270"))))
'(linum ((t (:inherit default :foreground "#777" :height 80)))))
)
short-circuiting the x-display-pixel-width and allowing Emacs starts cleanly from a remote terminal session. Since window-system also can tell you if you are on a Mac (or NeXT, if you are into retrocomputing) or under Windows (you can't argue taste), you can take appropriate actions according to your environment.
I am happy for today.
Mining the Social Web, by Matthew A. Russell
This book covers a lot of ground. It's, at times, a bit vertiginous in the amount of subjects and technologies it touches per chapter, and is not always easy to follow. It can also introduce so many interesting things that, by the time you finished becoming familiar with all of them, after wandering for hours on the web, jumping from interesting technology to interesting technology, you may have forgotten what took you to these places and wonder where you were in the book. Time spent reading it is, however, time very well spent. When you finish it, you will have at least a cursory familiarity with tools like OAuth, CouchDB, Redis, MapReduce, NumPy (and the Python programming language, albeit it will help you a lot if you know your way around Python before you start the book), Graphviz, SIMILE widgets, NLTK, various service APIs and data formats, and will be well equipped to explore those rich datasets on your own. The chapters are well compartmentalized and it's easy to pick chapters to read according to your needs. I know that, when I face the problems they tackle, I will do exactly that.
If you do any kind of analysis and visualization of social-generated data that's on the web, this book is a good pick. Even if your datasets are not from the web, you may find the parts on analysis and visualization very interesting.
You can find this book at the O'Reilly website or on Amazon.
Disclosure: I reviewed this book for the O'Reilly Blogger Review Program. If you have a blog and love to read, you should take a look into it. It's fun.
On "Closure: The Definitive Guide" by Michael Bolin
“Closure: The Definitive Guide” by Michael Bolin does a nice job on explaining a battle-tested, very complex tool that helps maintaining very complex JavaScript codebases manageable and understandable. Appendix B itself is worth the book, as it explains many of the JavaScript quirks to newbies and made me learn I was not as good as I thought I was. The world would be a better place if all JavaScript programmers read the appendix.
The rest of the book is what I expected - it teaches the reader how to build an application using Closure to your advantage, making your code more future-proof, browser-proof, more expressive, verifiable and testable. It covers the Closure Library, the Closure Compiler (a tool able to compile your JavaScript code into very compact JavaScript and Java that runs on your server - and, maybe, your mobile too), templates, widgets, AJAX, automated building and debugging. While we learn all that, the author also teaches us about the process of making a Google-sized web application. If you are at all familiar with JavaScript, the idea of doing a huge application is terrifying. After reading the book, while still scary, at least if feels possible to mere mortals.
If you are feeling the pressure of maintaining a big JavaScript project and is considering selling management the idea of migrating it to a JavaScript framework that encourages good practices (JavaScript makes it very easy to shoot yourself in the foot), this may be the book for you.
You can grab it directly on the O'Reilly web site. The e-book version comes without DRM and has Kindle, ePub, PDF and Android versions.
