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.

R (R- project for statistics)

糟糕透顶的字符串支撑 对于一些简单的描述任务，比如交叉表格，是非常困难的 大型数据集操作是在内存中完成的。

Python:

Global Interpreter Lock - Dealing with this complicates parallel processing. Lambdas functions are a bit clunky. No built-in ordered-dictionary type. Depending on how Python is compiled, it can use either UCS-2 vs UCS-4 for the internal Unicode encoding, many string operators and iterators may have unexpected results for multi-byte characters that exceed the default width. String slicing and iteration depend on the bit width rather than checking and counting characters. (Most other programming languages do similar things as well and have similarly odd behavior with these characters.) There are inconsistencies surrounding GUI frameworks for Python.

Clojure

Lack of built-in syntax for optional and keyword parameters in function definitions. Sure, you can add it easily enough, but that means library writers don't use it. Pervasive destructuring hasn't proven to be a good substitute yet Lack of method combination (before/after/around methods of the sort found in Common Lisp) Too much reliance on Java interop, e.g. there's no built-in file IO Sometimes I want static typing. This one isn't pure hate; I usually prefer dynamic, and attempts to mix the two have been largely unsatisfactory There's no built-in fast binary serialization format for the built-in data structures, though I hear people are working on it

Python:

处理数字太慢了。这不是什么大问题，除非…… 不能简单地在程序中包含导入时自动编译的C代码。 在py3k接管之前，我们仍然要忍受愚蠢的整数除法规则。 在py3k接管之前，像imap和izip这样的好东西仍然存在于一个单独的模块中。 在py3k接管之前，我们还有很多工作要做。

C#

我知道这很愚蠢，但我希望数据类型转换为我自己想要的，而不是我必须添加(int)或转换。ToInt32或者别的什么。这样可以节省我的时间。让我烦恼的是，如果我写了一些东西来输出一个int型，结果我需要一个long型，然后我经常不得不从头到尾修改我所做的一切来让它工作。就为了我!

抱歉，我想不出5个，但我是新手，所以也许我以后会回来添加更多:P