3 ms·

Can Your Programming Language Do This? (2006)

17 points by swyx 2y ago

fire_lake 2y ago
This article proved to be right - now all mainstream languages have some kind of lambda functionality. What’s next? My predictions are: - expression orientated - algebraic effects
- armchairhacker 2y ago
  Further along: affine types, refinement types, formally verified preconditions/postconditions, maybe even dependent types.
  - sterlind 2y ago
    Automatic theorem provers are stuck in AI winter. Pre/post-conditions and dependent types currently need too much handholding. Once the AI firms deign to release heuristic language models for proof discovery, we can have nice things like that.
    - alpine32 2y ago
      [dead]
wk_end 2y ago
Closures and stuff are great, but for the sake of being ornery: function Cook( i1, i2, f ) { alert("get the " + i1); f(i1); f(i2); } Cook( "lobster", "water", PutInPot ); Cook( "chicken", "coconut", BoomBoom ); (or worse) Cook("lobster", "water", function(x) { alert("pot " + x); } ); Cook("chicken", "coconut", function(x) { alert("boom " + x); } ); This to me looks like a great example of The Wrong Abstraction. You're removing a tiny bit of code duplication at the cost of creating a weird, hard-to-read, inflexible, limited-use helper; he's taken something straightforward and turned it into, honestly, a bit of a hash.
Jtsummers 2y ago
https://news.ycombinator.com/item?id=14882880 https://news.ycombinator.com/item?id=14882880 - July 29, 2017 - 2 comments https://news.ycombinator.com/item?id=2476440 https://news.ycombinator.com/item?id=2476440 - April 23, 2011 - 110 comments https://news.ycombinator.com/item?id=2209970 https://news.ycombinator.com/item?id=2209970 - February 12, 2011 - 1 comment Couldn't find more, but I thought it had come up more times.
sixthDot 2y ago
As people already commented in 2011, that's pretty common.
kazinator 2y ago
> Many older languages simply had no way to do this kind of stuff. Mainly due to not cribbing from other older languages like Lisp and Algol 68.
jkaptur 2y ago
> In fact, if you have two CPUs handy, maybe you could write some code to have each CPU do half of the elements, and suddenly map is twice as fast. I remember this came up a lot in late-aughts functional programming discussions. But is there any language where this actually works? Where map is just parallel because of course it is?
- _se 2y ago
  https://docs.rs/rayon/latest/rayon/iter/index.html https://docs.rs/rayon/latest/rayon/iter/index.html
- sterlind 2y ago
  F# defines a parallel map with the same type signature as sequential map, but you have to ask for Array.Parallel.map rather than Array.map or whatever, because of the possibility of side effects. Only in a pure language like Haskell could you safely parallelize automatically. I'm not sure why Haskell doesn't - maybe overhead?
  - recursivecaveat 2y ago
    I think it's pretty much impossible to tell statically whether you're going to be drowning in overhead spinning up a thread for every pixel on the screen, or leaving tons of parallelism on the table. Maybe with PGO it can be made to work. Even if it could be automatic, parallelism can be so important, and usually requires explicit design to enable, you probably don't want to delegate it.
- bluesnowmonkey 2y ago
  Elixir does this with Task.async_stream. https://hexdocs.pm/elixir/Task.html#async_stream/3 https://hexdocs.pm/elixir/Task.html#async_stream/3
eternityforest 2y ago
Programming sure has come a long way. This is all common now, he was completely right, and it's exactly as awesome as it sounded when it was new.
bdjsiqoocwk 2y ago
Does anyone else think that none of this is really that important? Really, not having to name a function and using it inline is an important feature, compared to defining it just before? And map is a lot more powerful than a for loop? I get the argument that its a nice to have, but does it justify a post called "can your language do this"? Really?
- deleted 2y ago
  [deleted]

17 points by swyx 2y ago

This article proved to be right - now all mainstream languages have some kind of lambda functionality. What’s next? My predictions are: - expression orientated - algebraic effects

armchairhacker 2y ago
Further along: affine types, refinement types, formally verified preconditions/postconditions, maybe even dependent types.
- sterlind 2y ago
  Automatic theorem provers are stuck in AI winter. Pre/post-conditions and dependent types currently need too much handholding. Once the AI firms deign to release heuristic language models for proof discovery, we can have nice things like that.
  - alpine32 2y ago
    [dead]

wk_end 2y ago

Closures and stuff are great, but for the sake of being ornery: function Cook( i1, i2, f ) { alert("get the " + i1); f(i1); f(i2); } Cook( "lobster", "water", PutInPot ); Cook( "chicken", "coconut", BoomBoom ); (or worse) Cook("lobster", "water", function(x) { alert("pot " + x); } ); Cook("chicken", "coconut", function(x) { alert("boom " + x); } ); This to me looks like a great example of The Wrong Abstraction. You're removing a tiny bit of code duplication at the cost of creating a weird, hard-to-read, inflexible, limited-use helper; he's taken something straightforward and turned it into, honestly, a bit of a hash.

Jtsummers 2y ago

https://news.ycombinator.com/item?id=14882880 https://news.ycombinator.com/item?id=14882880 - July 29, 2017 - 2 comments https://news.ycombinator.com/item?id=2476440 https://news.ycombinator.com/item?id=2476440 - April 23, 2011 - 110 comments https://news.ycombinator.com/item?id=2209970 https://news.ycombinator.com/item?id=2209970 - February 12, 2011 - 1 comment Couldn't find more, but I thought it had come up more times.

sixthDot 2y ago

As people already commented in 2011, that's pretty common.

kazinator 2y ago

> Many older languages simply had no way to do this kind of stuff. Mainly due to not cribbing from other older languages like Lisp and Algol 68.

jkaptur 2y ago

> In fact, if you have two CPUs handy, maybe you could write some code to have each CPU do half of the elements, and suddenly map is twice as fast. I remember this came up a lot in late-aughts functional programming discussions. But is there any language where this actually works? Where map is just parallel because of course it is?

_se 2y ago
https://docs.rs/rayon/latest/rayon/iter/index.html https://docs.rs/rayon/latest/rayon/iter/index.html
sterlind 2y ago
F# defines a parallel map with the same type signature as sequential map, but you have to ask for Array.Parallel.map rather than Array.map or whatever, because of the possibility of side effects. Only in a pure language like Haskell could you safely parallelize automatically. I'm not sure why Haskell doesn't - maybe overhead?
- recursivecaveat 2y ago
  I think it's pretty much impossible to tell statically whether you're going to be drowning in overhead spinning up a thread for every pixel on the screen, or leaving tons of parallelism on the table. Maybe with PGO it can be made to work. Even if it could be automatic, parallelism can be so important, and usually requires explicit design to enable, you probably don't want to delegate it.
bluesnowmonkey 2y ago
Elixir does this with Task.async_stream. https://hexdocs.pm/elixir/Task.html#async_stream/3 https://hexdocs.pm/elixir/Task.html#async_stream/3

eternityforest 2y ago

Programming sure has come a long way. This is all common now, he was completely right, and it's exactly as awesome as it sounded when it was new.

bdjsiqoocwk 2y ago

Does anyone else think that none of this is really that important? Really, not having to name a function and using it inline is an important feature, compared to defining it just before? And map is a lot more powerful than a for loop? I get the argument that its a nice to have, but does it justify a post called "can your language do this"? Really?

deleted 2y ago
[deleted]