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Comment by keyist | Hacker News Reader

"Between semicolon-free folks and JavaScript traditionalists, who gets to play the role of the expert?"

You're framing this as a disagreement between equals. It is not. There are degrees of expertise. (Total lines of production code * amount of usage) is a reasonable approximation, and those who rank highest on this scale are overwhelmingly in favor of requiring semicolons.

If Carmack and Torvalds were in agreement on a C best practice while Odesker^W^W^W^W^W^W^W Topcoder user #12571 said to do something else, I wouldn't go with the latter.

Google, responsible for a JS engine, multiple compilers that target JS, and what is likely to be the single largest JS codebase of any company: http://google-styleguide.googlecode.com/svn/trunk/javascript...

Brendan Eich: "The moral of this story: ASI is (formally speaking) a syntactic error correction procedure."

Or you can go with the Node.js guys.

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You can think about the effect of coding style instead of letting the experts think for you.

If you are doing a Topcoder round, then the random Topcoder user's advice is probably better than Carmack's. Carmack or Torvalds would probably tell you to use a variable name that gives a lot of information about its purpose, so that other people will find it easier to read your code. The Topcoder user might tell you to use a cryptic abbreviation that helps you remember a variable's purpose but clues little to the outside reader, since Topcoder users are penalized for allowing others to find their bugs. When implementing an algorithm, Carmack or Torvalds would code it as part of an extensible system with an API so that it can be used for many purposes. The Topcoder user might code it with no potential for reuse, but would do it in the way easiest to code quickly without making a mistake.

"You can think about the effect of coding style instead of letting the experts think for you."

Right, because what could those experts possibly have to teach you? Fuck that intellectual crap, brogrammers are here to crank out some code yo! Just because those dinosaurs have spent "thousands of hours" studying and trying out different programming styles and concepts means I should listen to them? This is the internet age man. Some guy in a github comment told me different and github is cool.

It's like those functional programming professors who try and talk about how continuation passing style was a bad road to go down because of maintenance problems and how difficult refactoring and just reasoning about code becomes in large systems.

Fuck that egghead noise, node.js has callbacks and node is how you get webscale.

I'm right with you bro!

You completely and utterly missed the point, in addition to just being needlessly rude.

The point of your parent was "don't let the experts think for you", not "screw the experts" - that's a very important distinction. You should form your own opinions, not just uncritically adopt the opinion of some expert. It's unquestionable that expert knowledge and experience is important - but nothing beats forming your own (hopefully informed) opinion.

Who said "let the experts think for you"? No one. You were arguing against "give the experts' opinions more weight than others, often a lot more"

"You should form your own opinions, not just uncritically adopt the opinion of some expert."

False dichotomy again, there is a lot of ground between "uncritically adopt the opinion of some expert" and "forming your own opinion and hoping it's informed".

You should find that middle ground, it's where all the smart people are.

I didn't miss the point at all, I just completely disagree with you. I don't think it was needlessly rude either, it was sarcastic. And I feel no need to treat people who are promoting anti-intellectualism with kid gloves.

Intellectualism is not about showing off how much you agree with authorities. Intellectualism is about thinking and understanding, eventually until you become one.

When discussing coding style, you can quote experts. Or you can understand their arguments, understand the impact and tradeoffs of coding decisions, and realize why they are true. And in the case of Topcoder, about as far as possible from building large systems, you can realize that the optimum style changes and understand why.

I think there's a broad trend to treat code as magic, something where anything can happen. Most people learn coding styles by being given suggestions, and then noticing from experience that they like it better. If you reject this mindset and believe that code is orderly, then this advice changes from Wisdom of the Elders (TM) into an engineering calculation. I specialize in automated restructuring of software architecture, so this mindset is something I try hard to fight against.

I don't see how this applies to me taking issue with the parents "figure it out yourself instead of letting the experts think for you" statement.

"Intellectualism is not about showing off how much you agree with authorities"

My point was that intellectualism is not about agreeing with authorities but giving proper weight to the opinions of intellectuals in the field when weighed against lay opinions or smaller groups of intellectuals.

You certainly don't seem to be arguing for the post-modern interpretation I was arguing against where expert opinion is considered "just another opinion, equally valid" so I'm confused why you think my stance is almost the opposite of what I was stating.

The opinion of an intellectual is indeed stronger Bayesian evidence than that of a layperson. But if they have an opinion, they should provide an argument to back it up, and that argument is far more important.

My first comment hit the advice to always follow Carmack over the random Topcoder user. It's important to understand what makes a best practice a best practice rather than just listening. A Topcoder round and Quake differ greatly enough that the random Topcoder user is sometimes the greater authority.

You seemed to map the call to critically evaluate expert opinion to a call to ignore it, something I'm sure you've seen too much of. But it's important to understand the difference between critical evaluation and anti-intellectualism. Indeed, the former is the higher form of respect.

In general I agree completely, standard philosophy of science stuff.

I'm not sure how well it applies to a subject like best practices where it's either subjective or at least fuzzy. The arguments are "in my experience this causes problems when working with other people and is more prone to errors long term". There have been no counter examples or analysis I've seen around this issue, just a "that's just what the traditionalists say" type argument. Something along the lines of your topcoder example that applied to the semicolon argument (god i hate this issue) would be very welcome.

Any critical analysis here is hard to do objectively, and there is a consensus of experts (including Eich) on one side. If i'd seen any actual critical analysis rather than a jump to "don't let the experts tell you what to do! be a rockstar!" then I wouldn't been so fast to use the anti-intellectualism card. But it's so prevalent in the node community (more than Ruby's but less than PHP's) that it's depressing.

The reason for using semicolons in JS is quite simple: It makes it easy to determine the boundaries between statements, both for humans and machines.

With semicolons, the search for the boundary between statements reduces to the search for that single character -- that means fast code skimming.

The boundary is also robust against changes; as long as that semicolon stays in place, nothing that happens within that statement can cause that boundary to become an interior.

There is an exception: Strings. This is no trouble for machines, as strings are processed by the lexer. Humans can't instantly take a string and process it as a chunk, but a UI innovation does this work for us: syntax highlighting.

As an example, consider the code:

  x = a && b
  foo()

If I try to change the "b", I might accidentally turn the code into

  x=a &&
  foo()

The grammar allows the malformed statement to interact with its neighbor, and thus, instead of getting a parser error, I'll get a program bug.

LR parsers take advantage of this for error recovery, allowing them to find more than one parse error at a time.

A more sophisticated view is to think about syntax abstractions. Given a program like "x=y; return x;" we can create a program written in the abstract syntax "statement; statement". (The dual operation is to concretized that back into the set of all two-statement programs. This kind of relationship is known a Galois connection.) Having semicolons makes the abstract syntax unambiguous, allowing us to efficiently reason at the statement level.

We're so off track that it's been lost that all my points are very definitely pro-semicolon?

You asked for an analysis of why semicolons are good, and you got it.

Brandon Eich on twitter (or in comments here) will also say that it is his opinion, and he recognizes that it seems to work pretty well for the NPM guys, but maybe it is just because they are such great devs, he doesn't see it scaling down that well.

And google is well known for terrible quality javascript. http://www.sitepoint.com/google-closure-how-not-to-write-jav...

And finally, Crockfords reasoning about things like this seems based on the presumption that js developers are drooling idiots. For example, he recommends against using the new keyword for object creation in javascript, even though object factories can often be a huge waste of memory, because dumb javascript developers may forget to use the new keyword at times when they want to instantiate objects.

I am not saying you shouldn't listen to smart people, but I am saying that you should actually learn the reasons they say the things they do, and use your own brain when making choices.

Brendan Eich does not oppose ASI.

Error correction simply means "add a semicolon if it's necessary."

He does oppose it being thought of a syntactic feature, ie part of the syntax.

He says it should be thought of as an error correction feature.

That is: do not in any case rely on ASI. Add your semicolons and only let ASI do it works when you do an actual ERROR and forget to add one.

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