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> There's at least a dozen languages you could have chosen, and that others have chosen for any given use case. within some bounds, it makes very little differe

> There's at least a dozen languages you could have chosen, and that others have chosen for any given use case. within some bounds, it makes very little difference. It's about quality of life and picking the right tool for the job. There are some problems I can solve in Haskell, that I simply could not solve in Java, it would be too hard and too much work. Java is a simple language and therefore it's much easier to reason about the performance and space usage. There are thus many problems where Java would be a better fit.

sesm 6y ago
Java is much easier to reason about the performance and space usage because it's a language with strict evaluation. Most programming languages use strict evaluation, including OCaml, F# and Scala.
- willtim 6y ago
  > because it's a language with strict evaluation But that is not the only reason. Haskell does much more aggressive optimisations than Java (and Scala, OCaml, F#). A large part of Haskell's space-usage reasoning issues come from the combination of lazy evaluation and these aggressive optimisations. Java and Scala code can contain plenty of deferred evaluation too, for example iterators, but the compilers simply don't do (and cannot do) such aggressive optimisations. Of course, this also means that much pure functional Scala/Java code can be poorly performing.
- Albert_Camus 6y ago
  Author here. Having written a lot of Haskell, I don't find lazy evaluation to be an issue nearly as often as it is a benefit. Yes, it can be difficult to reason about at times, but more often it ends up leading to simpler code. I would say that if you're consistently highly concerned with evaluation order, then yes, Haskell might not be the language for you. But I would also say that you shouldn't be concerned with evaluation order when writing Haskell, in the same way you usually shouldn't be concerned with what the query optimizer is doing when writing SQL.

sesm 6y ago

Java is much easier to reason about the performance and space usage because it's a language with strict evaluation. Most programming languages use strict evaluation, including OCaml, F# and Scala.

willtim 6y ago
> because it's a language with strict evaluation But that is not the only reason. Haskell does much more aggressive optimisations than Java (and Scala, OCaml, F#). A large part of Haskell's space-usage reasoning issues come from the combination of lazy evaluation and these aggressive optimisations. Java and Scala code can contain plenty of deferred evaluation too, for example iterators, but the compilers simply don't do (and cannot do) such aggressive optimisations. Of course, this also means that much pure functional Scala/Java code can be poorly performing.
Albert_Camus 6y ago
Author here. Having written a lot of Haskell, I don't find lazy evaluation to be an issue nearly as often as it is a benefit. Yes, it can be difficult to reason about at times, but more often it ends up leading to simpler code. I would say that if you're consistently highly concerned with evaluation order, then yes, Haskell might not be the language for you. But I would also say that you shouldn't be concerned with evaluation order when writing Haskell, in the same way you usually shouldn't be concerned with what the query optimizer is doing when writing SQL.