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That's functional programming for you. It's definitely less efficient, but there are other major advantages. For one thing, given the propagation of immutable d

That's functional programming for you. It's definitely less efficient, but there are other major advantages. For one thing, given the propagation of immutable data, things can be parallelized effortlessly - look at 'pmap' in Clojure for example. Once you're familiar with the style, it's significantly more concise and readable. That being said, a systems programming language may not be the right place for FP concepts.

saryant 13y ago
Scala gets around this with "views": store the higher-order functions until the collection actually needs to be used and then apply them all at once, without any intermediate data structure. http://docs.scala-lang.org/overviews/collections/views.html http://docs.scala-lang.org/overviews/collections/views.html
coolsunglasses 13y ago
>That's functional programming for you. Uhm, what? No it's not. Haskell has stream fusion, thereby generating assembler that looks a lot like the optimal imperative version.
- rybosome 13y ago
  Very cool - I was not aware of this feature. Fwiw, I'm actually something of an FP zealot; I failed to make a stronger case in my comment because I'm tired of arguing, and I'm concerned that I'm being obnoxious.
- burntsushi 13y ago
  This is kind of misleading. Stream fusion isn't baked into Haskell; you need to use a library. [1,2] [1] - https://ghc.haskell.org/trac/ghc/ticket/915 [2] - http://hackage.haskell.org/package/stream-fusion
  - danieldk 13y ago
    But, many of the commonly used libraries already use stream fusion, e.g. vector and text.
  - coolsunglasses 13y ago
    http://hackage.haskell.org/package/text-0.1/docs/Data-Text-Fusion.html http://hackage.haskell.org/package/text-0.1/docs/Data-Text-F... http://hackage.haskell.org/package/vector-0.9.1/docs/Data-Vector-Fusion-Stream.html http://hackage.haskell.org/package/vector-0.9.1/docs/Data-Ve... Except it's bloody everywhere in the libraries you use and you can design your own libraries around it. A language powerful enough that things like this can be done in libraries instead of in the compiler is a good thing.
Dewie 13y ago
> That being said, a systems programming language may not be the right place for FP concepts. It's good enough for Rust.
- pcwalton 13y ago
  Note that the Rust compiler doesn't do any stream fusion; rather the functional idioms are designed around iterators, which provide a functional interface that relatively easily and predictably compiles down to code that's as efficient as the corresponding for loop.
- rybosome 13y ago
  I wondered about that - Rust looks like the one systems programming language I would actually enjoy using, but I don't know enough about it to have an informed opinion.
krakensden 13y ago
> things can be parallelized effortlessly If you're not using a language with Clojure's nifty datastructures, "effortlessly" probably isn't much better than OpenMP.
atilaneves 13y ago
D is a systems programming language with FP concepts and they work quite well. Also, it has generics / templates / parametric polymorphism that are more powerful and easier to use than C++.
- chongli 13y ago
  Right, but it still employs a machine model of computation. This is fundamentally different from FP's language model. https://existentialtype.wordpress.com/2011/03/16/languages-and-machines/ https://existentialtype.wordpress.com/2011/03/16/languages-a...

saryant 13y ago

Scala gets around this with "views": store the higher-order functions until the collection actually needs to be used and then apply them all at once, without any intermediate data structure. http://docs.scala-lang.org/overviews/collections/views.html http://docs.scala-lang.org/overviews/collections/views.html

coolsunglasses 13y ago

>That's functional programming for you. Uhm, what? No it's not. Haskell has stream fusion, thereby generating assembler that looks a lot like the optimal imperative version.

rybosome 13y ago
Very cool - I was not aware of this feature. Fwiw, I'm actually something of an FP zealot; I failed to make a stronger case in my comment because I'm tired of arguing, and I'm concerned that I'm being obnoxious.
burntsushi 13y ago
This is kind of misleading. Stream fusion isn't baked into Haskell; you need to use a library. [1,2] [1] - https://ghc.haskell.org/trac/ghc/ticket/915 [2] - http://hackage.haskell.org/package/stream-fusion
- danieldk 13y ago
  But, many of the commonly used libraries already use stream fusion, e.g. vector and text.
- coolsunglasses 13y ago
  http://hackage.haskell.org/package/text-0.1/docs/Data-Text-Fusion.html http://hackage.haskell.org/package/text-0.1/docs/Data-Text-F... http://hackage.haskell.org/package/vector-0.9.1/docs/Data-Vector-Fusion-Stream.html http://hackage.haskell.org/package/vector-0.9.1/docs/Data-Ve... Except it's bloody everywhere in the libraries you use and you can design your own libraries around it. A language powerful enough that things like this can be done in libraries instead of in the compiler is a good thing.

Dewie 13y ago

> That being said, a systems programming language may not be the right place for FP concepts. It's good enough for Rust.

pcwalton 13y ago
Note that the Rust compiler doesn't do any stream fusion; rather the functional idioms are designed around iterators, which provide a functional interface that relatively easily and predictably compiles down to code that's as efficient as the corresponding for loop.
rybosome 13y ago
I wondered about that - Rust looks like the one systems programming language I would actually enjoy using, but I don't know enough about it to have an informed opinion.

krakensden 13y ago

> things can be parallelized effortlessly If you're not using a language with Clojure's nifty datastructures, "effortlessly" probably isn't much better than OpenMP.

atilaneves 13y ago

D is a systems programming language with FP concepts and they work quite well. Also, it has generics / templates / parametric polymorphism that are more powerful and easier to use than C++.

chongli 13y ago
Right, but it still employs a machine model of computation. This is fundamentally different from FP's language model. https://existentialtype.wordpress.com/2011/03/16/languages-and-machines/ https://existentialtype.wordpress.com/2011/03/16/languages-a...