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But Haskell does stand out among your list as being a pure functional programming language (it is not the only example of course). Whether this is a good or bad

by willtim 10y ago

But Haskell does stand out among your list as being a pure functional programming language (it is not the only example of course). Whether this is a good or bad thing, I will not get into. When programming in a pure language you typically have to use some quite recent/advanced ideas such as monads and lenses, just to get practical work done. This is not the case with Clojure, F#, Scala, Erlang etc, where side-effects are idiomatic. In fact, if you tried to go fully pure with these languages, you would run into problems with performance. To avoid confusion, they should have used the term "pure functional programming" or even "typed pure functional programming".

jarcane 10y ago
To avoid confusion, they should have used the term "pure functional programming" or even "typed pure functional programming". That's what was used when I started learning FP, which was maybe three or four years ago. There was FP, and then purity was a secondary characteristic. Haskell was pure and typed, but that didn't make other languages not FP, when they still had all the same basic tools and the same idiomatic focus on composition of functions over mutable state and imperative logic. No, you didn't need a special magic word to allow you to have side-effects like I/O, and most also allowed for mutability (even Scheme had set! after all), but they are first and foremost functional languages. In many ways, Haskell was and still kind of is the odd one out, not counting experiemental academic languages like Idris and Coq. This wasn't even a controversial statement just a few years ago. But as Haskell has been more and more in vogue, there's this weird fixation on redefining the window of what "FP" is to only refer to, well, Haskell. And it's very clearly what the LC list is all about, because so many of the concepts described are both largely unique to Haskell and it's closest relatives, and unnecessary to do practical, everyday work in a vast majority of FP languages. And ultimately, attitudes like that hurt the whole field. In trying to fix Haskell's image problem by brute force, they wind up damning the larger domain in the process.

by willtim 10y ago

jarcane 10y ago

To avoid confusion, they should have used the term "pure functional programming" or even "typed pure functional programming". That's what was used when I started learning FP, which was maybe three or four years ago. There was FP, and then purity was a secondary characteristic. Haskell was pure and typed, but that didn't make other languages not FP, when they still had all the same basic tools and the same idiomatic focus on composition of functions over mutable state and imperative logic. No, you didn't need a special magic word to allow you to have side-effects like I/O, and most also allowed for mutability (even Scheme had set! after all), but they are first and foremost functional languages. In many ways, Haskell was and still kind of is the odd one out, not counting experiemental academic languages like Idris and Coq. This wasn't even a controversial statement just a few years ago. But as Haskell has been more and more in vogue, there's this weird fixation on redefining the window of what "FP" is to only refer to, well, Haskell. And it's very clearly what the LC list is all about, because so many of the concepts described are both largely unique to Haskell and it's closest relatives, and unnecessary to do practical, everyday work in a vast majority of FP languages. And ultimately, attitudes like that hurt the whole field. In trying to fix Haskell's image problem by brute force, they wind up damning the larger domain in the process.