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Ask HN: On Rob Pike's Concurrency is not Parallelism?

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Re: Ask HN: On Rob Pike's Concurrency is not Parallelism?

#61

Post by silentbicycle »

rvirding wrote: post #59
silentbicycle wrote: post #56

Earlier quoted context omitted.

It takes a lot of chutzpah for Larry Wall to say anything critical about Lisp syntax. Larry Wall. Come on . I'm not the author of the comment above, but I think Erlang's syntax is effective in that it strongly emphasizes computation by pattern matching. If you write very imperative code in it (as people tend to, coming from Ruby or what have you), yes, it will look gnarly. Good Erlang code looks qualitatively differe…

As in Prolog ',' and ';' are separators: ',' behaves like an and , first do then and then do this (as in Prolog); while ';' is an or , do this clause or do this clause (again as in Prolog). '.' ends something, in this case a function definition. Erlang's functions clauses are not the same as Prolog's clauses which explains the difference. It is very simple really, think of sentences in English and it all becomes triv…

Indeed. It makes sense to me. Are my intuitions about the origins of ;s separating top-level clauses accurate?

(Hello, Robert! :) )

Re: Ask HN: On Rob Pike's Concurrency is not Parallelism?

#62

Post by rademi »

silentbicycle wrote: post #56
zem wrote: post #53

Earlier quoted context omitted.

these things are very much a matter of taste. what does "effective" mean with respect to syntax? for instance, lispers will argue that their syntax is effective because of the things it lets you do, but that's orthogonal to whether it's actually a pleasant syntax to program in, which comes down to personal taste[1]. likewise, i love mlish syntax, but opa, a language steeped in ml semantics, nonetheless switched to so…

It takes a lot of chutzpah for Larry Wall to say anything critical about Lisp syntax. Larry Wall. Come on . I'm not the author of the comment above, but I think Erlang's syntax is effective in that it strongly emphasizes computation by pattern matching. If you write very imperative code in it (as people tend to, coming from Ruby or what have you), yes, it will look gnarly. Good Erlang code looks qualitatively differe…

To be fair, that was Larry Wall reacting to criticism in 1994 https://groups.google.com/forum/?fromgroups#!msg/comp.lang.l...

Anyways, my experience is that all languages will get people criticizing them. And, in my experience, those kinds of criticisms should almost always be categorized as "does not want to talk about language FOO" and a proper response is probably something like "if you don't want to give that subject the respect it deserves, let's change the subject to something you find interesting".

Re: Ask HN: On Rob Pike's Concurrency is not Parallelism?

#63

Post by tholschuh »

preist wrote: post #55
tholschuh wrote: post #46

Earlier quoted context omitted.

If you like Erlang but cannot get past its syntax you might want to give Elixir a try. http://elixir-lang.org/

Syntax looks very Ruby like.

Is that good or bad? I personally don't mind Erlang syntax at all or the syntax overhead to you have to write a gen_server that does nothing. Elixir saves you some of that overhead. It's kind of like CoffeeScript for Erlang. It's fully compatible since it compiles to Erlang AST which compiles to BEAM. You can do "everything" with Elixir you can do with Erlang. Of course, you have to understand how to work with Erlang/OTP to actually benefit.

Re: Ask HN: On Rob Pike's Concurrency is not Parallelism?

#65

Post by sausagefeet »

zem wrote: post #53
KirinDave wrote: post #51

Earlier quoted context omitted.

Honestly? Erlang's syntax is not that bad. It's not great in that it has prolog legacy with uncanny valleys to C-legacy left and right, but it's effective. Really the only really tricky thing for a newbie is strings.

these things are very much a matter of taste. what does "effective" mean with respect to syntax? for instance, lispers will argue that their syntax is effective because of the things it lets you do, but that's orthogonal to whether it's actually a pleasant syntax to program in, which comes down to personal taste[1]. likewise, i love mlish syntax, but opa, a language steeped in ml semantics, nonetheless switched to so…

Erlang syntax maybe jarring but one benefit of it is there is actually very little syntax relative to languages like Java, C++, Python. There isn't that much to hold in your head. I can switch between Erlang and another language pretty effortlessly because the context switch is so small.

Re: Ask HN: On Rob Pike's Concurrency is not Parallelism?

#66

Post by rvirding »

silentbicycle wrote: post #61
rvirding wrote: post #59

Earlier quoted context omitted.

As in Prolog ',' and ';' are separators: ',' behaves like an and , first do then and then do this (as in Prolog); while ';' is an or , do this clause or do this clause (again as in Prolog). '.' ends something, in this case a function definition. Erlang's functions clauses are not the same as Prolog's clauses which explains the difference. It is very simple really, think of sentences in English and it all becomes triv…

Indeed. It makes sense to me. Are my intuitions about the origins of ;s separating top-level clauses accurate? (Hello, Robert! :) )

Sort of. The syntax evolved at the same time we were moving from Prolog onto our own implementation, which forced us to write our own parser and not rely on the original Prolog one. The biggest syntax change came around 1991, since then it has been mainly smaller additions and adjustments.

Re: Ask HN: On Rob Pike's Concurrency is not Parallelism?

#67

Post by angelbob »

KirinDave wrote: post #60
ryah wrote: post #37

Earlier quoted context omitted.

Node is popular because it allows normal people to do high concurrency servers. It's not the fastest or leanest or even very well put together - but it makes good trade offs in terms of cognitive overhead, simplicity of implementation, and performance. I have a lot of problems with Node myself - but the single event loop per process is not one of them. I think that is a good programming model for app developers. I lo…

I do not see how you can simultaneously care about making programming better but not care about how people use what you're making to solve that problem. Programming is a verb describing what people do with programming systems, and we're nowhere near the point where it can be done automatically yet. You cannot remove people from the equation and claim to be interacting with it.

I think he's saying he wants to make programming better for newbies.

It really kinda sucks for them right now.

Serious hard-core engineers that need serious tools are actually pretty well served by current tools. No, no, they're not perfect. But we're way better off than somebody who's just beginning in terms of what tools are aimed at us.

Re: Ask HN: On Rob Pike's Concurrency is not Parallelism?

#68

Post by tjholowaychuk »

ryah wrote: post #37
KirinDave wrote: post #33

Earlier quoted context omitted.

You know, ryah; I like your work ethic, I like your enthusiasm, I think you're a cool guy and it's great your project has so much traction. But you say things like this and it worries me. Because a lot of people look up to you and either you said this because you feel defensive about your project or you said it because you genuinely don't understand the cases we're talking about here. And this is a problem because a…

Node is popular because it allows normal people to do high concurrency servers. It's not the fastest or leanest or even very well put together - but it makes good trade offs in terms of cognitive overhead, simplicity of implementation, and performance. I have a lot of problems with Node myself - but the single event loop per process is not one of them. I think that is a good programming model for app developers. I lo…

Agreed, and as computing grows messaging will just get cheaper and cheaper. zeromq is a great example of that, 5 million messages per second over TCP on a macbook air is not half bad.

Personally I like static typing, especially if somewhat optional, it's something we effectively do through documentation anyway (via JSdoc or similar), but makes it concrete.

I dont think light-weight threads sharing memory is so bad, symmetric coroutines are more or less the same as an event loop IMO, the thought put into working with them is more or less identical, just without callback hell and odd error-handling, but I suppose going all-out with message passing could be fine. I think that's still a bit of an implementation detail unless you get rid of the concept of a process all together and start just having a sea of routines that talk to each other.

Re: Ask HN: On Rob Pike's Concurrency is not Parallelism?

#69

Post by dano »

ryah wrote: post #37
KirinDave wrote: post #33

Earlier quoted context omitted.

You know, ryah; I like your work ethic, I like your enthusiasm, I think you're a cool guy and it's great your project has so much traction. But you say things like this and it worries me. Because a lot of people look up to you and either you said this because you feel defensive about your project or you said it because you genuinely don't understand the cases we're talking about here. And this is a problem because a…

Node is popular because it allows normal people to do high concurrency servers. It's not the fastest or leanest or even very well put together - but it makes good trade offs in terms of cognitive overhead, simplicity of implementation, and performance. I have a lot of problems with Node myself - but the single event loop per process is not one of them. I think that is a good programming model for app developers. I lo…

I think the reaction from many long-term programmers who have switched technologies, careers, frameworks, languages is to the "...use it for everything?" mantra. I applaud your goals and the success at getting more people to program and build things. That's what we really do need. Let's hope this audience is reading HN with an open mind and figure out, as many here have, that the problem to be solved is the most important decision, not the tool.

Thank you for the nice write up.

Re: Ask HN: On Rob Pike's Concurrency is not Parallelism?

#70

Post by Xantix »

The difference between Concurrency and Parallel is in my opinion somewhat subjective, depending on how you view the problem.

Examples of Concurrency:

1. I surf the web And I run an installer for another program.

2. One gopher brings empty carts back, while another brings full carts to the incinerator.

The idea of concurrency is that two completely separate tasks are being done at the same time. There may be synchronization points between the two tasks, but the tasks themselves are dissimilar.

Viewed in one way moving empty wheelbarrows may be completely different from moving filled ones.

Viewed in another way, they might seem very similar.

Concurrency has to do with task parallelism.

Parallel has to do with data parallelism.

There's a gray line between the two where you can't clearly differentiate between them.

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