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.

Erlang不在此列表中。在我最喜欢的语言中，但有一些缺陷是肯定的:

Syntax. This includes the 3 terminating tokens (,;.) and aesthetics, but more generally on how the semantic meaning of the code is expressed in text. An example is on how all lowercase tokens are atoms, so to refer to a function you can't just name it, you have to fun my_function/1, and ?PRECEDE_CONSTANTS_WITH_QUESTION_MARKS. Coming from Scheme, Haskell, etc. you just wish you could use a name. Library support is lame. This is mostly external libraries, but even the old standard library. Newer versions of Erlang have sensible POSIX regexes, but the old one had a pretty horrible library for basic string manipulation. You also never know when you're getting the value, or {ok, Value}. Related: non-uniform tools for building and distribution. Ruby has gem and rake, RSpec. Perl has CPAN. I'm unaware of decent equivalents in Erlang. The few Erlang specific tools are pretty strange. Mnesia is a great database, but coming from SQL you have lots of trivialities to learn. Same with the documentation @spec, which has a strange way of describing signatures. Often the functional paradigm hurts when you just want that little bit of mutation. Supposing you want a Hash Table, you can't just hack it as in Scheme, or SML. ets and dets alleviate some of the pain, but not much.

第六,奖金:

模块的导入和导出语法是一堆失败，这与Java的80多行导入语句没有什么不同。

综上所述，Erlang是一种乐趣^_^

Haskell:

空间泄漏——懒惰的默认代价——也许代价太高了? 甚至像head和tail这样的纯函数也会调用错误并引导您进入IO。 fail from Monad -带回MonadZero。 Num类-(+)应该在AdditiveGroup或类似的类型中。 那个单子不是一个应用程序。

C#

Lack of multiple dispatch based on the runtime type of the method arguments. dynamic should solve most of this, but it hasn't been released yet. Interface implementation is declarative not structural. I really like the way Google's Go language is doing types Making asynchronous method calls is really bulky (and I'm pretty sure all threads are OS threads, not lightweight threads) No macro system. I'm not talking about C-style macros here; I'm talking LISP/Scheme style macros Operators are static methods and their signatures are overly constrained (and you can't create new ones).

Python

没有名称空间。 伪私有属性/名称混淆(主要使用getattr)。 文件路径操作分布在多个模块中。串在一起的os。路径调用是丑陋的，难以读取，并且在大多数情况下违反了DRY。常见的文件路径操作仍然没有方便的函数，比如获取目录下的文件列表。修复此问题的路径类型模块被拒绝。

([f for f in os.listdir('/file/path') if os.path.isfile(os.path. isfile)加入(/文件/路径,f))))

Python文档(我非常、非常、非常感谢有文档，而且它的格式很好，但我讨厌费力地在5000行快速入门使用示例中找到特定模块的单个函数文档(我正在查看optparse和logging))。内置类型在近10个不同的地方被零碎地记录。

Java

已检查的异常 类型擦除 缺少操作符重载(例如BigInteger/BigDecimal) 缺少regexp/date/duration /复杂文字 对不可变性的支持很差