Recent blog entries for benad

Exploring Reactive Programming

A few months ago, I discovered the oddly-named JavaScript library "bacon.js". Essentially, it lets you declare and compose event channels. While it seems overly abstract, the sample code intrigued me, as it introduced me to what is called "reactive programming".

Let's put this in context of typical UI programming. Let's say you want to write a GUI with a button that initiates a file download. You can't simply make the download synchronous, as it would "freeze" the entire GUI. The classical way to handle that is to create a new background thread that executes the download and also sends appropriate GUI events to display the state of the download.

The problem with that approach is that if you change the GUI, you now have to not only change the code that gets called when the download button is clicked, but also all the GUI updates done by the background thread. The GUI logic is intermingled with all the logic to start the thread, also intermingled with the download logic proper.

In more modern concurrency interfaces, the GUI code can spawn a new "Future", and describe what should happen when it completes outside of the code the Future will execute. This works well if the GUI doesn't have a download progress bar of some kind, and makes the download logic free of GUI logic. Still, this is risky: If for any reason the GUI vanishes (window closed, etc.), there is no easy way for the code related to the button click to describe how to cancel the background download, and when.

This is where "event channels" come into play. The most known implementation are the UNIX shells, where you would "pipe" one process' output to another's input. If the first process is terminated, the second process will get an interruption event when it attempts to read from the pipe, which by default cause the second process to be terminated. This is an easy way to create process groups, without having to explicitly tell the kernel about it.

Similar "process group" patterns exist in programming languages that support event communication between pseudo-processes or threads, for example the OTP Supervisor in Erlang.

Even will all of this (Futures, process pipes, supervisors), there are still a few things missing to make the implementation of a GUI download button simpler. First, there is no easy way to connect changes to mutable values, if the download button is active or not for example, to an event channel, and vice-versa. Basically, we need some kind of observer pattern, but applied to event handling. This has been my main gripe about MVC since, well, a long time ago. Also, there is no easy way to compose event channels together, even something as simple as aggregating multiple channel sources together into a new channel. While all that isn't terribly new in the networking world, with things like ZeroMQ and so on, in a programming environment without unreliability inherent in networking and no need for an interoperable packet-oriented stack, combining "networking" events together as a design pattern is quite compelling.

Hence why I was intrigued by bacon.js. It was inspired by the more comprehensive RxJs by Microsoft, and complements the React JavaScript library by Facebook. In fact, there even is a reactive programming manifesto, though it may be more the result of consultants hungry for the next wave of buzzwords than anything else. Still, it feels like what Aspect-Oriented Programming did to the Inversion of Control pattern, but applied to asynchronous event-based programming, which is to say that it brings it to a whole new level.

Syndicated 2015-09-15 23:46:57 from Benad's Blog

10s Everywhere

So recently I installed Windows 10 on my MacBook Pro alongside Mac OS X Yosemite 10.10. If you're keeping count, that's four 10s.

Upgrading Windows 8.1 to 10 was a strange experience. First, the Windows 10 notification icon never showed up. Looking at the Event Logs of GWX.exe ("Get Windows 10", I guess), it kept crashing with "data is invalid" for the past few months. Yet, the same logs showed clearly that my license was valid and ready to be upgraded to 10. Luckily, Microsoft now offers the Windows 10 ISO download, and the software used to download and "burn" a USB key also allowed for an in-place upgrade with no need for a USB key or DVD.

Yet, after the upgrade, I noticed that all network connections were disabled. Yes, the Boot Camp drivers were installed correctly, and Windows insisted the drivers were correctly working, but it's as if the entire TCP stack was removed. I tried everything for a few hours, getting lost in regedit, so I gave up and used the option to revert back to Windows 8.1. Once back, it was now worse, with even all keyboards disabled.

Before reverting back to 8.1, I attempted to remove all 3rd-party software that could have an impact on the network, including an old copy of the Cisco VPN client and the Avast anti-virus. The Cisco VPN client refused to be uninstalled for some reason. Back on 8.1, I could easily remove the VPN client (using the on-screen keyboard), but it's as if 8.1 kept trace of the Avast install even though Avast was not there anymore. Luckily, I found the download link to the full offline Avast 2015 installer in the user forums. After doing so, both the keyboard and the network were enabled.

Having learned that VPN and Anti-virus software can break things in Windows 10, I uninstalled all of these, and then upgraded to 10 again. I had to reinstall the Boot Camp drivers for my model of MacBook Pro, and this time everything was working fine. I could restore easily Avast, but the old Cisco VPN driver clearly couldn't work anymore. This isn't a big issue, since I keep a Windows 7 virtual machine for that.

What about using Boot Camp in a virtual machine? Well, there are two workarounds I had to do to make it work with Parallels Desktop. First, Article ID 122808 describes how to patch the file C:\Windows\inf\volume.inf so that Parallels can detect the Windows 10 partition. It just so happens that I already had my copy of Paragon NTFS for Mac, so changing the file when booted in the Mac partition was easy. Then, from Article ID 116582, since I'm using a 64-bit EFI installation of Windows, I had to run their strange script. It needs administrator privileges, so I temporarily enabled that on my user account to run it. After all of this, Windows got a bit confused about the product activation, but after a few reboots between native and virtual machine modes, it somehow picked up the activation.

So, what about Windows 10 itself? For me, It worked fine. It isn't a huge upgrade compared to Windows 8.1, but it's more usable in a desktop environment. For Windows 7 users, I would definitively recommend it, maybe after a few months until they fix the remaining bugs. As usual, backing up your files is highly recommended (even if you don't upgrade).

Syndicated 2015-08-02 19:57:31 from Benad's Blog

A Code's First Draft

Incremental software development, or evolutions of it, is now pretty much the standard approach, as we now expect requirements to be changed all the time. But this too easily leads to "over engineering", as since we expect change at all times, we spend too much effort on maximizing the flexibility of the code over any other quality.

I admit that in the past I too fell into the trap of over engineering my code, for the sake of "beautiful design" over functionality, making the code far too unnecessarily difficult to understand. From that experience, I now make incremental design changes more reactively.

Practically, it means that I always make a "first draft" of my code with minimal design, and then, based on that experience, make a second draft with a first draft of the design, all that before the first wave of requirements changes. This is quite different than software prototyping, where the first iteration is expected to be deleted or completely rewritten over time. In my case, most of the code of the first draft remains, but moved and refactored to fit the first design change.

The first code draft is done primarily as a proof of concept that demonstrates feasibility, to reduce future risk as much as possible. That way, regardless of future design or functional changes, at least we have a simple functional version of the code. That first draft could even be used as some "sample pseudo-code" to document the functional mechanism of the code, outside of the design and architectural complexities that are added later on as the software grows. That implies that the first code draft should be so clear and simple that it is (almost fully) self-documented.

Secondarily, it helps in making worthwhile design decisions early. Once you have working code, it's easier to see what design patterns would be useful, and precisely where. You can see in context the costs and benefits of each design pattern, and only those that are worth it are applied as a first design iteration. Once additional features are added or existing one changed some new design decisions may be needed, but if by the time of the second draft you have sound code and design, it will be easier to adapt than if you greedily made inappropriate or unnecessary design choice.

At some point, though, the extra effort in doing design changes on top of purely functional coding changes may be too costly if requirements changes are chaotic or indisciplined. This may be why so many programmers invest in design upfront while they have the chance, dooming the code to over engineering. The software engineers may be the only ones in the software development process that can present (and defend) the impact of endless changes on quality (bad code, inappropriate design, etc.), so over-design may be indicative of greater organizational issues.

Syndicated 2015-06-01 02:18:25 from Benad's Blog

The Mystery of Logitech Wireless Interferences

As I mentioned before, I got a new gaming PC a few months ago. Since it sits below my TV, I also bought with it a new wireless keyboard and mouse, the Logitech K360 and M510, respectively. I'm used to Bluetooth mice and keyboards, but it seems that in the PC world Bluetooth is not as commonplace as in Macs, so the standard is to use some dongle. Luckily, Logitech use a "Unifying Receiver" so that both the keyboard and mouse can share a single USB receiver, freeing an additional port. In addition, the Alienware Alpha has a hidden USB 2.0 port underneath it, which seems to be the ideal place for the dongle and freeing all the external ports.

My luck stopped there though. Playing some first-person shooters, I noticed that the mouse was quite imprecise, and from time to time the keyboard would lag for a second or so. Is that why "PC gaming purists" swear by wired mice and keyboards? I moved the dongle to the back or front USB ports, and the issue remained. As a test, I plugged in my wired Logitech G500 mouse with the help of a ridiculously long 3-meter USB cable, and it seems to have solved that problem. But I remained with this half-working wireless keyboard, and with that USB cable an annoying setup.

I couldn't figure out what was wrong, and willing to absorb the costs, until I found this post on the Logitech forums. Essentially, it doesn't play well with USB 3.0. I'm not talking about issues when you plus it the receiver in a USB 3.0 port, since that would have been a non-issue with the USB 2.0 port I was using underneath the Alpha. Nope. Just the mere presence of a USB 3.0 in the proximity of the receiver creates "significant amount of RF noise in the 2.4GHz band" used by Logitech. To be fair (and they insist on mentioning it), this seems to be a systemic issue with all 2.4GHz devices, and not just Logitech.

So I did a test. I took this really long USB cable and connected the receiver to it, making the receiver sit right next to the mouse and keyboard at the opposite side of the room where the TV and Alpha are located. And that solved the issue. Of course, to avoid that new "USB cable across the room" issue, I used a combination of a short half-meter USB cable and a USB hub with another half-meter cable to place the receiver at the opposite side of the TV cabinet. Again, the interference was removed.

OK, I guess all is fine and my mouse and keyboard are fully functional, but what about those new laptops with USB 3.0 on each port? Oh well, next time I'll stick to Bluetooth.

Syndicated 2015-05-03 21:48:04 from Benad's Blog

Electricity Savings: All Those Blinking Lights

As part of my "spring cleaning", and partly inspired by this "Earth Hour" thing, I did an inventory of all the connected electrical devices around my apartment.

I basically categorized them this way:

  1. Devices that are used all the time and must be connected: Lights, electrical heating, fridge, water heater and so on.
  2. Devices that are seldom used, but cannot be turned off completely or disconnected easily: Oven, washer, dryer, and so on.
  3. Devices that are on all the time, for some reason.
  4. Devices that are used enough to warrant leaving them in "low-power standby mode".
  5. Devices I should turn off completely or disconnect when not used.

While I can't do anything for the devices in categories 1 and 2, other than replacing them, my goal was to move as many devices to either standby or turned off as possible. For example, my "home server PC", a Mac mini, doesn't use much power, but do I really need to have to running all the time? So I programmed it to be in standby, and wake up only during the afternoons on weekdays.

For devices already in standby mode, are they used enough? For example, my Panasonic Blu-Ray player kept being warm, since it remained in standby mode, for what? About 10 seconds of boot time? Since my TV takes that much time to "boot up" anyway, I just need to power on both at the same time, and I'll save all the electricity of keeping it in standby all the time.

I am generally less worried about laptops, tables and other battery-operated mobile devices when they stand in standby. They are already quite energy-efficient, running on batteries or not, especially when not actively used. Still, unplugging them from chargers reduces risks if there's an electrical surcharge in the apartment's wiring.

Syndicated 2015-03-30 20:26:00 from Benad's Blog

Alpha: My First PC

The PC port of Final Fantasy VII that I recently completed was the first of many PC-only games I wanted to play, but queued up because playing PC games is inconvenient. I have a 2011 Mac mini that I can dual-boot in Windows, which is what I mostly used for FF VII, but rebooting was slow, the mini was noisy, and its graphics card simply unable to properly play games made after 2010. I have a late-2013 MacBook Pro, but I keep using it for work, it's inconvenient for playing on a TV, and its graphics card could have been better.

I insisted on using Macs, even for PC games, because "gaming PCs" are just too much trouble. Almost all small-form-factor PCs sacrifice graphics performance for size and quieter fans, including the mini. On the other end, even your average "gaming PC" is expensive, a bulky tower with neon lights and require manual assembly. Here's the thing: I can do all of that without problem, from building a PC server to maintaining Windows Server. But that's what I do at work. It's as if there is not such thing as a "casual gaming PC for your TV". Well, at least until the Alienware Alpha, essentially a small-form-factor gaming PC.

The Alienware Alpha is presented as a kind of video game console. While it runs Windows 8.1, its default user account is running a modified version of XBMC that replaces the Windows desktop, and lets you run Steam in "Big Picture" mode. The entire setup can be done (a bit clumsily) using the provided XBox 360 controller (oddly, with its USB dongle for wireless use). For me, though, I already had my wireless mouse and keyboard (and a USB mouse with a long USB extension of FPS games), because I want to play older PC games made for a mouse and keyboard, so I ultimately disabled that "full screen" account and set up a standard desktop Windows account.

And you have to accept that the Alienware Alpha is a PC that isn't that user-friendly and requires tweaking to play games. For example, the frame rate of "Metro: Last Light" was terrible because it was using outdated nvidia libraries; updating the library files made the game much faster. Or Geometry Wars 3 had terrible lag issues, until you run it in windowed mode or manually edit its settings file. Actually, the simple fact that the Alpha's nvidia card is "too new" to be recognized by older games is enough to force you to tweak all the settings. I'm still curious about dual-booting into SteamOS, a Linux distribution of Steam that has a proper "console feel", though most games I want to play are PC-only or not in Steam in the first place (from GOG, actually).

With all that said, the Alpha is a pretty good PC. I was able to plan all the games at maximum settings at at least 30 frames per second, and much more on games made before 2012. It's well optimized for 1080p, which is less than 4K support from current-gen 3D gaming cards, but is perfect for TV use. The hard drive is slower than my MacBook Pro's SSD, but the 3D card is so much better on the Alpha that I don't mind the extra load time. You can still easily replace the hard drive in the Alpha with a SSD, and you can upgrade pretty much everything else but the motherboard and 3D chip, with detailed service manuals. It has an HDMI passthrough, digital optical audio output, many USB 2 and 3 ports (and even a hidden USB port underneath, perfect for my wireless keyboard dongle). Finally, its price is competitive, meaning absurdly cheap compared to similar specifications from Apple.

What I'm saying is that the Alienware Alpha is a good "entry-level" casual gaming PC for use on a TV, without the hassle of a typical PC tower. That, and I now have a PC. I still feel a bit weird about that.

Syndicated 2015-01-14 00:33:59 from Benad's Blog

The Last Retro Final Fantasy

Going back to my previous post, I'm a bit relieved that Final Fantasy VII didn't live up to its hype. And what hype. When released in 1997, it was backed by the unprecedented weight of Sony making it the flagship game of their first foray in video game consoles. The game was marketed everywhere as a kind of "movie as a game", placing emphasis on the FMVs (part of a $100 million publicity campaign, including television and cinema, for 3 months). For many, Final Fantasy VII was their first video game experience.

Let's step back a bit and look at its predecessor, Final Fantasy VI (named "Final Fantasy III" on Nintendo platforms). Its setting was exactly halfway between "Dungeons and Dragons" style of fantasy and Shinto-style fantasy in the present day. It does so by making its setting a world where magic vanished for a thousand years and the world evolved into a "steampunk" style. It successfully explains, through its story, the source of magic in this world, including deep ethical considerations of its use.

The game presents the story through a large group of characters, without a clear, single "hero", and this is done deliberately so as an important theme later in the game. The dramatic elements are at times mature and dark, yet presented subtly (as if to evade Nintendo's sensibilities), dealing with themes of death and suicide unseen on a kid-friendly game platform before. For years I found the game to dark for my liking, the same way I disliked Zelda: Majora's Mask. The themes in Final Fantasy VI are perfectly integrated with the gameplay, visual art and music. Speaking of which, the game's graphic design and music are masterpieces of their authors, Amano and Uematsu.

But Final Fantasy VI was too weird. Being overly focused on its artistic statements, it doesn't please enough neither Western nor Japanese sensibilities. A cross between steampunk and Dungeons and Dragons, with multiple narratives and realism like Game of Thrones? That's not what kids want? And so with VII they started pandering to their audience, with anime-like effeminate "Japanese Boy Band" characters, over-the-top drama presented with in-your-face imagery that make Evangelion subtle, lots of FMVs and cool characters, and since they won't really like RPGs anyway, let's throw as many mini-games in there as possible.

Over time, they became niche of their own captive market anyway. But mass-market appeal pretty much died out with Final Fantasy: Spirits Within, meaning that people that never played any Final Fantasy are unlikely to even try the latest instalments. Still, the damage was done. A new generation of video game players didn't really cared about gameplay, but more the over-pretentious low quality movie experience that surrounds it. It's style over substance, and even if you focused on the art, it was superficial crap made for teenagers that didn't knew any better. The latest Final Fantasy XV trailer looks like an expensive car ad. Magical realism can only go so far before it becomes ridiculous (Zoolander, the game?).

Essentially, Final Fantasy VII and Sony started a movement that, by the mid-2000s, nearly destroyed the video game industry, temporarily saved by the Wii and morally questionable free-to-play games. Only with the recent raise of retro and indie gaming we are starting to see the market increase again.

All to say that I now hate Final Fantasy VII with a passion. Its predecessor is a timeless masterpiece, and I'm not saying this out of nostalgia or because I was influenced by marketing as a teenager. Final Fantasy VI is the best RPG I can recommend, and is now out on iOS and Android, also 50% off at $8 (Canadian Dollars) until January 5, 2015.

Syndicated 2014-12-31 01:49:20 from Benad's Blog

Final Fantasy VII, a Late Review

As I mentioned in a previous post, I started playing the game Final Fantasy VII so that I can, as objectively as possible, review it. I reserved my judgement until I complete the game, and 6 months later, or about 60 hours of game play, I finished it.

To be as fair as possible, I won't compare it to any of its predecessors in the series or its contemporaries in the genre, to see if it can stand on its own merits. I'll be lenient to what could have been caused by the technical limitations of the time (PlayStation 1), and even the problems introduced in the PC port of the game.


Since the game makes its story front and centre of the experience, I'll start here.

It is difficult to summarize the story succinctly. On the one hand, it is a story of "eco-terrorists" that attempt to prevent this "evil corporation" from siphoning the "life energy" of the planet into power plants, for evil reasons. This is the same energy that is the source, in concentrated jewel form, of magical powers in the game, called "material". Of course, ecology + modern electrical technology + power plants + Japan = Godzilla. Also, for some evil reasons, the "bad guy" attempts to crash a comet on the planet so that he can harness all of that "life energy" to destroy the world or something.

On the other hand, it's the story of the immature man-children that compose that team of "rebels". It is mostly focused on the placeholder hero, Cloud, with a bad case of amnesia for anything other than his hate for the "bad guy".

It's bad. The characters are wholly unlikable, or laughably generic ("Aerith the flower girl" is an actual main character name in the game). The "amnesia" thing, which lasts almost the entire game, feels like a desperate mean to fill in plot holes in an otherwise uninteresting story. Character motivations are paper thin and selfish, surprising since that whole "comet will soon destroy all life" would have implied that the motivation could have been as simple as "saving the world", but no, it's only about revenge and selfish personal reasons. Twists and turns in the story are either caused by the characters complete emotional immaturity, or Deus Ex Machina that makes the plot of "Lost" well planned in comparison.

In any other medium except anime this story would be considered bad. But then, maybe this game is just some kind of anime with some RPG elements slapped on top of it.


This game tries its hardest to mesh modern-day technology with fantasy elements, and it simply doesn't mix well. It also doesn't make sense why there could be such a world with modern warfare weaponry (automatic rifles, tanks, helicopters, planes) while magical items that allow anyone to perform magic is so commonplace. It's like Blade Runner with Japanese mystical elements of spirits and magic. It sounds really cool, yet this game manages to make it not work at all.

Oh, and the game never attempts to explain the impractically oversized swords of the hero, especially in a world with guns and magical powers.

Music and Sound

The sound elements are pretty bad in general.

The music has a few tracks that are quite good and memorable, but the rest of the time it's mostly a collection of fillers, even with repetition.


Let's start with the controls. In a battle, the camera's spinning makes it a challenge to properly target enemies. On the map, it feels like you're in a maze of invisible walls, with some that "slide along", and others that stop you in your tracks. Camera angles frequently change from one area to another, with little consistency in the controller directions, making simple movement difficult.

Before looking the RPG elements proper, let's look at the other "games": the puzzles, the "quick time events", and the mini-games. The puzzles are either too obtuse or easy. The "quick time events" are never good, in this game or elsewhere. The mini-games are completely different games than RPG, mostly racing, inserted into this game for some reason. You're forced to play each mini-game at least once, and each is horrible and would not stand on their own, so should be avoided as much as possible.

The RPG proper is fine, but not great. It is based around a "materia" system, those items that enable its wearer to perform magic. The materia items are placed into sockets in the weapon and armour of each character. Each materia has its own experience points, and when their reach higher levels they allow its wearer to perform more powerful attacks or at the highest level "spawn" a copy at level 1. Some materia can be paired with others to perform modifications.

Having only 3 characters in battles seems limited, and makes everything unbalanced if you lose a single one. This makes the game either a highly defensive one, or one when you want to defeat the opponent as quickly and safely as possible. You get a roster of up to 9 characters, but most of the time one of the 3 character choice is locked down to the "hero" Cloud, and there is little incentive to level up all the characters. At any rate, the characters are mostly interchangeable since their base stats and unique weapons are easily overwhelmed by the effects of the materia items. Given the emphasis on materia, setting up sets of materia on your characters takes a lot of time.

Speaking of time, the battles are too slow. Each attack takes several seconds to execute, and special attacks can take up to a minute. I avoided using the "summon materia" special attacks for that reason. Real-clock time became an important resource while playing this game, making "grinding" to level up characters take too much time.

Generally, the game as a lot of depth, but not enough to justify the 60+ hours of game time. Most of that time was stretched out from unnecessary long battle animations and unskippable cut scenes.


The game is fine, but not great. There are too many flaws and annoyances to merit playing it to the end. Its large budget is quite visible on screen, it has a lot of depth, but what was lacking was fun. The story was bad, the characters cliché and unlikeable, the battles slow, the controls poor, the mini-games horrendous, all atop of an average RPG.

Syndicated 2014-12-29 16:40:04 from Benad's Blog

Modern MVC in the Browser

A few months ago, I started learning the AngularJS framework for web development. It is a quite clever framework that allows you to "augment" your HTML with markup to map placeholders with elements in your object model. It reminded me of JSP and markup-based SWING frameworks I used a decade ago. Since then, though, I realized that this template-based approach has quite a few limitations that bother me. First, as it is based on templates, it doesn't handle well highly dynamic elements that generate markup based on context. Second, complex, many-to-many mappings between the view and the model are difficult to express. For example, it is difficult to express a value placeholder that is the sum of multiple elements in the models without having to resort calling a custom function, or having the change in the view trigger the corresponding change in multiple locations in the model without, again, resorting to a custom function. Third, it is a framework that needs to keep track of the model/view mapping, so it is all-encompassing and heavy in configuration.

So, let's break down the problem and look individually at the view, model and controller as separate modules, and see if there could be a better, more "modern" approach.

The biggest problem with the "model" in JavaScript is that it lacks safely hiding properties as functions, as done natively in C# for example, or manually through "getter" and "setter" functions in JavaBeans. Because of that, it becomes difficult to take any normal object and add a layer on top of it that would implement an observer pattern automatically. Instead, you can use something like the model implementation of Backbone.js that fully hides the model behind a get/set interface that can automatically trigger change events to listener objects. It may not be elegant, but it works well.

For the "view", HTML development doesn't support well the concept of a "custom control" or "custom widget" in other GUIs. The view is mostly static, and JavaScript can change the DOM to some extent, and at high cost. In contrast, other GUI systems are based around rendering controls ("GUI controls", not to be confused with the controller in MVC) on a canvas, and the compositing engine takes care of rendering on screen only the visible and changed elements. A major advantage of that approach is that each control can render in any way it pleases without having to be aware of the lower-level rendering engine, be it pixels, vectors or HTML. You could simulate a full refresh of the DOM each time something (model or controller) changes the GUI in HTML, but the performance would be abysmal. Hence, the React library from Facebook and Instagram, which supports render-based custom controls but using a "virtual DOM", akin to "bitmasks" in traditional GUIs, so that only effective DOM changes are applied.

Finally, for the "controller", the biggest issue is how to have both the model and the view update each other automatically, on top of the usual business logic in the controller, without creating cyclic loops. React's approach, named Flux, is a design pattern where you always let events flow from the model to the view, and never (directly) in the other direction. My gripe with that is that it is merely a design pattern that cannot be enforced. This reminds me of the dangers of using the WPF threading model as a means to avoid concurrency issues: Forget to use the event dispatcher a single time, and you will create highly difficult to debug crashes. A new approach, called functional reactive programming is kind of like what dependency injection did for module integration, but for events. Essentially it is a functional way of manipulating channels of events between producers and consumers outside of the code of each producer and consumer. This may sound quite an overhead compared to the inline and prescriptive approach of Flux, but as soon as you build a web page heavy on asynchronous callbacks and events coming from outside the page, having all of that "glue" in a single location is a great benefit. An implementation of FRP for JavaScript, Bacon.js, has a great example of how FRP greatly reduces those countless nested callbacks that are commonplace in web and Node development.

Combined, Backbone.js, React and Bacon.js offer a compelling alternative to control- and template-heavy browser MVC frameworks, and at minimum prevent you from being "locked-in" a complex and difficult to replace framework.

Syndicated 2014-11-26 01:44:49 from Benad's Blog

A Tale of Two Shells

Last year, I completed "properly" learning the bash ("Bash"?) shell, using a combination of the book "Learning the bash Shell" and reading from start to finish the gigantic "man" page. And that was enough to convince me that, regardless of its ubiquity, I don't like it much, be it as a scripting language or as a command-line shell.

Having already learned tcsh, because it was the default shell on Mac OS X and is still popular, I was ready to try out more modern shells, rather than ones stuck in the 80s.

First, on Windows, DOS is quite archaic and annoying. Simple things like sleeping for a second require unintuitive workarounds. DOS batch scripting is painfully difficult, so I was eager to find something better. And since Windows 7, this strange "PowerShell" is now installed by default, and was heralded as a revolutionary step in command-line shells. Is it?

After reading a few tutorials, including this "free ebook" on, things became clear. Windows PowerShell is essentially a shell built atop .NET that manipulates streams of objects rather than plain text across pipes, though thankfully formats the objects as plain text on the console screen by default. It provides many "cmdlets" that can manipulate that stream in a more convenient way than grep and awk. For example, listing all files in a directory greater than a megabyte is trivial in PowerShell, while on UNIX shell requires an awkward (pun intended) combination of extracting character positions and arithmetic. The "PowerShell IDE", also provided with PowerShell, can even perform tab-completion of the fields of the objects out of the current pipe, making it easy to extract their attributes. Because so much of the Windows internals are accessible using COM and .NET, it is easy to perform system administration with it, for example installing system services and querying their status. The only major issue I've found with PowerShell is that executing PowerShell scripts is completely disabled by default until unlocked by an administrator. Also, as a minor gripe, the version of PowerShell that came out of the box with Windows 7 is quite outdated. Overall, if there was a "grand vision" of ".NET" in Windows, it is best represented by PowerShell.

Back on UNIX-like systems, it seems like users are quite happy with old shells, or at least incremental evolutions of the old "Bourne shell" and Berkeley's "C Shell". Looking around, I found "fish", the "Friendly Interactive SHell". I liked its ironic tagline of "Finally, a command line shell for the 90s", since it was initially released in 2005. It is, indeed, friendly, as it has a deliberately limited set of features, and has default out-of-the-box functionality that makes interactive use enjoyable. It was built around a comprehensive design document that explicitly favours usability over compatibility with older or popular shells. The results are spectacular: Everything has colour, TAB and arrow keys completion with a type ahead preview in light grey, inline argument completion for most commands (including "man") that present interactively all the options and their meaning automatically extracted from the "man" pages, editing the configuration through a built-in web service, applying configuration changes to all shells instantly, I could go on. Its scripting is quite limited, but that may be a good thing considering the Shellshock bug (Not that "fish" has no security holes, but at least they're not "as designed").

Personally, I am ready to move to both PowerShell and "fish" for day-to-day use. While they both don't have much in common to older shells, they are far more usable. I highly recommend to all command-line users.

Syndicated 2014-10-28 01:37:41 from Benad's Blog

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New HTML Parser: The long-awaited libxml2 based HTML parser code is live. It needs further work but already handles most markup better than the original parser.

Keep up with the latest Advogato features by reading the Advogato status blog.

If you're a C programmer with some spare time, take a look at the mod_virgule project page and help us with one of the tasks on the ToDo list!