Scala是我最喜欢的语言。五件讨厌的事?容易:

Takes a long time to learn properly. I know you can write Scala as a 'better java'. That is what we used to say about C++ and C too. I agree this is an inevitable consequence of the deep ideas in the language. But still ... Methods vs. Functions: def f(x: Int) = x*x defines a method f, not a function f. Methods are not functions despite a lot of early Scala tutorial material blurring the distinction. The language tries to blur it too because if you supply a method in some places where a function is expected it is accepted. Do we have to have both methods and functions? Yes it is fundamental. But it was initially confusing to me. Composing classes or objects from mixins in the 'cake' pattern is prone to NPE's. e.g. trait X { val host: String; val url = "http://" + host } is a mixin that will NPE on instantiation, or not, depending on its position in the class declaration. The compiler could tell you if it will fail but doesn't. (In 2.7 anyway.) It is hard to diagnose the problem in complex inheritance graphs. Arrays in 2.8 rely on implicits to mesh with the main scala collection types. But implicits are not applied everywhere. An Array can be supplied where a Seq is expected. But an Option[Array] cannot be supplied where an Option[Seq] is expected. I know there are no completely 'right' ways to handle java Arrays. Type erasure. Enough said.

c#:

1)静态方法必须是类的成员

2)静态扩展方法只能添加到静态类中

3)接口函数的实现不会被标记为“override”之类的东西来显示它们来自基类或接口(这使得你很难确保你正在重写你所期望的方法(具有正确的签名))。

我只有3个。我想那很好。

Python:

1) line continuation syntax: "...\" works, but "...\ " does not, and that trailing space is generally invisible, without unusual eol-marking by editer. 2) a bare 'raise' is invisible in the stack trace, as the stack trace looks like the previous raised exception. 3) slow 4) poor integration into web-servers (mod_python: dead, mod_wsgi: limited scope of operation). This is complicated by 3], requiring daemonization or some sort of memory-persistance to perform well. 5) overly tolerant of mixed tabs and spaces, allowing changes to control flow to sometimes remain hidden. (maybe fixed in recent versions)

Haskell。

默认情况下导入Prelude。 类型类的范围是通用的。 模块不是一流的。 类型不能依赖于值。 单子不统一Functor。

我刚刚发现，在c#中创建泛型方法时，我不能使用Enum作为类型约束。

微软有一个足够好的解释，但仍然。我疯了

public static T MyFunc<T>(string arg) where T:Enum //wont work :(

Objective Caml

Non-concurrent garbage collector. I can write multi-threaded programs all day long, but they're only ever going to get one of my eight cores at a time. This makes me sad. No type classes (or their moral equivalent). There's Furuse-san's GCaml, but it's A) not quite as good as type classes, and B) not in the INRIA distribution. Badly in need of a Cocoa bridge. Seriously. If I wrote more code with actual interfaces to DNA-based life forms, then I'd probably break down and write the damned thing myself. Why hasn't anybody else done this yet? Functors are abominable. Seriously, modules ought to be first-class values. There should be only one kind of function. Read Montagu and Rémy before you flame me for this. Should use LLVM for its back-end. Who do I have to murder to get OCaml to compile for my stupid little ARM6 core?

是的，我有一些问题。我仍然非常喜欢这门语言。这太棒了。