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Haskell is good for most things. So lets focus on the ones specific to web development.Haskell offers quite a lot over other languages, even just for web development.ConcurrencyOne place Haskell really shines is concurrency. It's fair to say that it's well ahead of pretty much every alternative here.The base of the system are Haskell's green threads: these are lightweight threads managed by the language itself and mapped down to a smaller number of native OS threads. These threads are so lightweight that you can easily run millions on normal hardware. Millions! This gives you a very nice model for web programming: every request gets a thread. This leads to much simpler, easier to maintain logic, but you don't sacrifice performance: since the IO manager is intelligently implemented, your code ends up using an efficient event-loop even though it doesn't look event-based. Much like Node.js without any callbacks, except it's also intelligent enough to scale trivially over multiple cores. (And, I believe, faster.)On top of this, the very design of Haskell makes for fewer concurrency bugs. There are exciting technologies like Software Transactional Memory (STM) which present a nice model for shared-memory concurrency without a large programming penalty. I've talked to some people who have a Haskell trading system that they converted to using STM; they reported a performance loss of ~4%. Given the benefits, this is a no-brainer!STM, as well as the rest of Haskell's wonderful concurrency features are a very interesting topic but a bit too long for a single Quora answer. Happily, Simon Marlow (who is the most qualified person to talk about this) has written a very friendly book about this: Parallel and Concurrent Programming in Haskell. And, in the usual Haskell spirit, the book is available free online!Suffice to say: Haskell will solve most of your concurrency problems for you. Without making compromises on your programming model like Node.js's callback hell. The code you write still looks mostly like normal, single-threaded Haskell; it just scales really well.SafetyAnother classical benefit of typed functional programming is safety. For web programming, you still get all the type safety you would with normal programs. But there are also ways to use the type system to prevent common web programming problems.The Yesod Web Framework does a really good job of using Haskell's type system. The types statically prevent:XSS attacks: they ensure that user input is sanitized and prevent you from accidentally using unsanitized inputSQL injection: same idea with escaping SQL queriesother SQL errors: you query your database using normal Haskell constructs, which ensures SQL queries are well formedmissing template variables: even template variables are statically checked to make sure they exist and have the right typebroken links: the system ensures you never generate internal broken linkscharacter encoding issues: the type system makes sure that you never accidentally mix up text encoded in different waysMore importantly, it does all this without excessive boilerplate. This is not Java! Haskell provides a bunch of advanced tools like global type inference and Template Haskell which lets you get away with as little keyboard typing as a dynamically typed language but with far more static typing :).A side note about Template Haskell: just like the name implies, it's very good for, well, templates. This makes it very easy to embed HTML/CSS/JS templates in your code in intelligent ways—the results of templates are first-class citizens, which means you can pass them around, build functions from them and so on. It means that your inline HTML snippets use the same syntax and have the same functionality as your large full-page templates, with everything being really easy to combine.Coincidentally, Yesod also has an O'Reilly book you can read. And it's also available free online: Developing Applications with Haskell and Yesod.So don't worry about not having enough (free!) learning resources!ExpressivenessPeople generally assume that, since Haskell is compiled, offers all these great features and has significant static guarantees, it has to be less expressive or more verbose than dynamically typed languages like Python. In my experience, this is not the case: Haskell is actually more expressive than many languages like Python.Haskell has a few characteristics that make this possible:type inference: since types are inferred globally, you almost never have to write them out unless it makes your code clearerabstraction: Haskell has really good facilities for making high-level, reusable abstractions which save a lot of code in the long run.flexibility: Haskell is flexible enough to admit good-looking DSLs for things like querying databases—you need far less boilerplate for these taskslibraries: Haskell has a surprising amount of general-purpose libraries that can be used in a whole bunch of contexts like lenses, which let you work with nested data types. (They're like "jQuery for nested data types".)functional programming: finally, functional programming is naturally more concise than imperative programming, especially with Haskell's more minimal syntax.typeclasses: typeclasses allow you to write code that would not be possible in other languages. Combined with type inference, they get rid of a lot of redundant module/class names in other languages.I've written a few (admittedly small) things in both Haskell and Python. Most of the time, the Haskell has fewer lines of code even though it's also statically typed and faster. What's not to like?I think this is a very compelling set of capabilities for more effective web programming. It makes Haskell well worth learning! Remember that learning the language is an O(1) operation whereas the benefit you get is O(n) based on how much you use it!Also, empirically, it's not nearly as hard to pick up as people make it out to be. One of my friends recently started using Haskell at IMVU—switching from PHP!—and they had no real problems getting the rest of the developers (who had not had any functional programming experience) working efficiently with Haskell. Both hiring and training aren't nearly the obstacles that you would imagine if you just read internet complaints about Haskell.The engineer at IMVU responsible for bringing in Haskell has written a great blog post about it (What it's like to use Haskell); it's worth a read if you're considering Haskell as an option.

One part logistics, two parts politics.The United States was the “big stick" of NATO in the 50s against the USSR and Communism, with other signatories still rebuilding shattered cities and economies after WWII. As such, the US had significant power in negotiations regarding standardization of ammunition, a key problem in WWII as practically every participating country had its own ammunition standards, none of which were compatible with any other.While the British were working on an idea developed from the StG 44, the world's first “assault rifle", the US thought the resulting cartridge (the .280 British) was underpowered, and hawked its own cartridge based on shortening and slightly down-loading the 30–06 Springfield, producing the .308 Winchester which was NATOized as the 7.62x51mm. Other signatories agreed to accept this cartridge in return for a US promise to consider European rifles to replace its aging stock of M1 Garand rifles. While the Army did test the FN FAL and a couple other European designs, they ultimately went with the Garand-derived M14.… Which quickly proved itself far too difficult to control in automatic fire with an infantry rifle, which was the exact problem the British had been working to mitigate with the .280. The M14 was also heavy, its ammunition bulky, and its action too exposed to the environment. Casting around for a replacement that would reduce recoil and weapon weight while retaining lethality, they found the varminting and sport-shooting concept of “small-caliber, high-velocity".The short version of the concept is threefold. First, the name of the game in ballistics is “kinetic energy”. The kinetic energy equation is a function of the mass of a bullet, and the square of its velocity, unlike momentum (used in collision modelling) which is the simple product of mass times velocity. This means that given a bullet of a particular mass and muzzle velocity, a second bullet half the mass only has to go 41.4% faster than the first bullet to have the same kinetic energy, so you can, in theory, deal the same damage to a target using a smaller bullet fired from a smaller cartridge, allowing you to carry more cartridges for the same weight and bulk.Second, being small and fast is how you defeat armor; the smaller the footprint of the collision between projectile and armor, the smaller the area that the force of the projectile’s collision is dissipated across, and as the objective is not simply to damage the armor, but to get through it to damage what’s underneath, you want as little energy as possible to be dissipated into the armor so the projectile can instead do damage underneath it. And third, a faster bullet covers the distance between the muzzle and the target in a shorter time, meaning gravity has had less time to pull the bullet down toward the center of the earth. This creates a “flatter” ballistic arc, and a longer “point-blank range” where no compensation for the ballistic arc of the bullet is needed; just line the sights and pull the trigger and you will be close enough.Army brass also remembered this little subsidiary of Fairchild Aircraft that had submitted a novel entry in the M14 competition, which worked surprisingly well until its experimental aluminum barrel blew up. The Army asked Eugene Stoner and his Armalite team if they could scale down the Armalite Rifle Model 10 to fire a round Remington was developing based on its successful .222 Special target round. The result was the AR-15 chambered in .223 Remington, both militarized as the M16 and the 5.56x45mm respectively.European NATO members, for their part, were aghast. Not only did the US totally organically come to the same physics and logistical conclusions European weapons designers had already reached a decade prior, they'd also once again ignored their allies' options and input, unilaterally introducing yet another “standard” to the NATO armory while European factories were still turning out battle rifles in the previously-agreed 7.62x51mm. The new 5.56 was therefore slow in adoption among European nations; however, the Soviets were impressed by what they saw from it in Vietnam (despite the AR's teething troubles and the U.S.’s more strategic difficulties in that war), and rechambered their own Kalashnikov-pattern infantry rifles in a similarly-minded 5.45x39mm round, producing the lesser-known AK-74 which still forms the base for Russian army AKs like the current AK-15. The larger-bored AK-47s and AKMs were then sold at fire-sale prices to any military or paramilitary organization willing to stand up and say they opposed the Western powers (most of which couldn’t have cared less about Cold War politics, but hey, cheap rifles).Seeing their own enemy adopt the concept, European NATO countries capitulated, but also put their foot down. They would adopt the 5.56x45, if the U.S. would honor its earlier commitment to adopt a European firearm design, this time choosing a European sidearm and its cartridge. The U.S. Army and Marines, in another example of stubbornness and “if it ain’t broke”, was still using the WWI-era M1911 handgun and its larger .45ACP cartridge that had now seen the US through four major wars. The pistol was generally well-liked by soldiers, and fired a large round well-suited to stopping enemies in close-quarters situations, but ammunition capacity was a problem and field-stripping a bit of a pain compared to newer designs being introduced in the late 70s and early 80s. The USAF had already largely abandoned the M1911 for a slate of civilian-market pistols and revolvers, and the Navy was threatening to follow suit, presenting a logistics nightmare for the Joint Chiefs and an increasingly integrated military supply chain.Western Europe, in the meantime, had all but standardized around the 9mm Luger cartridge that had seen Germany through two wars, and was also becoming popular in the US to replace the .38 Special as the standard police sidearm chambering. Like the .223, it was smaller than its predecessor, but faster, and gun manufacturers both in Europe and Stateside were developing double-stacked pistol designs that dramatically increased ammunition capacity.Seeing that it had burned a significant amount of goodwill among NATO signatories with the rifle cartridge debacle, and also having little to lose as sidearm stocks were being reduced to focus on the rifle as the centerpiece of an infantryman's capabilities, the U.S. agreed to the compromise. Beginning in 1977, a joint selection committee auditioned several European designs including Sig Sauer's P226 and Beretta's 92FS, alongside entries from Walther, HK and Steyr from Europe and US mainstays Colt and Smith & Wesson, ultimately choosing the Beretta as the M9.The US did insist that the pistols be produced in American factories by American workers, which Beretta obliged by creating a wholly-owned US subsidiary rather than licensing the design to an existing US maker. That arrangement worked out so well for Beretta that many other major European names including Glock, Sig Sauer, FN and HK have since followed suit, both for easier negotiation of government contracts and to skirt the Gun Control Act’s restrictions on firearm imports for the civilian market. The US also requested that the round be standardized a little “hotter” than current SAAMI and CIP specifications to make up some kinetic energy from the .45ACP it was giving up. That loading, producing about 5% higher chamber pressure than a standard-pressure Luger cartridge, was standardized as the 9x19mm NATO.

Yes and no. Our city was divided into two zones - north and south. Within those zones were smaller 'beats,' which represented an officer's area of responsibility. During the yearly bid, you had a chance to request a sergeant for a given zone; once you were assigned to a sergeant, that sergeant would give you a request form for beat preference. You then listed your top three choices for beats. They were assigned based on a few factors:Seniority. Years of service talk; if you're the senior officer on the squad, you're essentially going to get your choice of beat, with some rare exceptions.Officer Specializations. If you have specialized training, you may be encouraged/assigned into a certain beat. If you're a DRE (Drug Recognition Expert) with equal seniority with someone else, you may get slotted downtown, simply due to the likelihood you'll be paged in to conduct testing.Professional Development. If a first or second year officer, in the sergeant's opinion, needs to hone their skills in a certain area of response, they may get slotted in a beat where that skill will be exercised more often than in other beats. For instance, if an officer has accident response down but is a little shaky on domestic disturbance calls, the sergeant may slot them where there are more domestics just to round them out as an officer down the line.These aren't equal; in fact, I'd say these break down to 85/8/7, respectively. So why would an officer choose one beat or another? Well, beats aren't created equal. I'll walk you through the beats in my old beloved Zone One; the city has completely revamped their system, so this is antiquated information. It's also indicative of night calls, as I only worked second and third shift.Beat 11: The largest beat in the zone; more heavily residential than commercial, with some major highways within it. Might be favored by an officer who likes traffic assignments (moving violations and accidents).Beat 12: Heavily residential with some strip malls at its western boundary, and featuring a major interstate interchange. Tended to feature more commercial and residential alarms, domestic incidents, and accidents. The accidents could get ugly fast - I once worked a four car injury accident caused by a DWI in this beat. (By myself, no less...not that you've got any basis for knowing why you should feel sorry for me here.) Honestly regarded as the suck-out beat though - you were far enough from downtown you could stay out of the fray there, and could typically duck a lot of stuff.Beat 13: West side; almost exclusively residential. Perhaps the lowest standard of living anywhere in the city. Domestic City - you're going to work a lot of them here. You also tend to get involved in downtown kerfuffles due to your proximity. I would say it suits someone who likes to throw down and take the streets by storm, but this is where I worked, and that was never my style. Even so, sometimes that kind of response is thrust upon you; if I needed to sling someone onto the pavement, I had no compunction in doing so - and the opportunity presented itself quite often here.Beat 14: Downtown. Usually seething with drunks, both in public and in their residences. You'll pull a lot of DWIs here, so you'd better at least be comfortable with them, if not in love with them. This beat takes an extra measure of discretion; there will be a lot of things you'll have to overlook downtown, because if you chuck the book at everyone you'll both run yourself ragged and make tons of enemies. This is definitely a beat where you're going to have to realize that public perception and goodwill are often worth exponentially more than rote enforcement.Beat 15: Southern end of town; features a mall and several large department stores, so it was very heavy on shopliftings - I sometimes worked three a shift. Also a lot of congested intersections in these districts, so there were tons of accidents as well. This was an incredibly busy beat on second shift, because both shopliftings and accidents spiked during the initial hours of that shift (just after 5:00 pm). Fairly coveted during third shift, though, because traffic was light and businesses were closed.Flex/Relief: Extra officers were assigned to be 'rovers' throughout the zone and pick up calls in beats when the beat officer was engaged elsewhere. In the absence of calls, they could back other officers up on calls or pick up a proactive pursuit. They were luxuries - I despised coming into work and hearing that we were "beats," which meant that we only had enough officers on duty to cover beats. Even worse was the rare circumstance where we were "open beat," which meant that we were an officer short of being able to cover beats.So what factors make one beat more desirable than another for an officer? That depends purely on an officer's personal interests.If an officer has an interest in DWIs, they may put in for Beat 14 or for Relief. Beat 14 would put them around downtown on a nightly basis, and Relief drivers would have more flexibility to look for them not being directly responsible for a beat.If an officer likes smaller beats where they can get out in the air and interact with people, they may pick 13 or 14. You can more quickly memorize the nooks and crannies and back alleys than in the larger beats, which is of immeasurable help when you scare up a foot pursuit.If an officer has an interest in traffic enforcement or working accidents, 11, 12, or 15 fit the bill. They all contained interstate mileage and high congestion intersections and interchanges.For drug calls, definitely 13, and 14 to a lesser extent. You'd find drugs in 13 without even trying. I've watched dime bags, pills and paraphernalia fall out of pants pockets, backpacks, vehicles, sun visors - you name it.Though they may be found in 13 and 14, no officer genuinely enjoys working domestics - they're completely soul-killing, no matter how you slice it. With genuine domestics, you pluck an abuser out of their home, making them more angry in the process, then put them in jail for what amounts to a five hour timeout. Then they're released with no bail or bond and usually picked up by their victim, who may be graced with the good fortune of not being hit until they get home. With ticky tack "domestics" (boyfriend hid girlfriend's keys, wife locked husband out of the house, and on and on), the reporting requirement was the same, forcing me to write a full police report for something as simple as a girlfriend calling her boyfriend stupid. Yeah. But, if a rookie needed to hone their skills here, they might get assigned to one of these beats.If an officer was interested in being lazy, 12 or 15, and stay south - dispatch sometimes dispatched by proximity to the call, so sluggards would mope around the edge of the city so they wouldn't get sent to anything outside of their beat. At their own peril, though - locker room chatter for these chaps was most unkind.