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.

REBOL

REBOL是我最喜欢的语言之一。我不能说我有一个最喜欢的，尽管Haskell排名也很高。

Its odd syntax scares off many developers before they even give it a try. use [email rules url] [ ; A small DSL that sends email to people about URLs. rules: [ some [ into [ set email email! set url url! (send/subject email url reform [ "Check Out" url ]) ] ] ] ; Global context notify: func [ [catch] dsl [block!] ] [ unless parse dsl rules [ throw make error! "You screwed up somehow." ] ] ] notify [ [ a@b.com http://www.google.com ] [ b@c.com http://www.yahoo.com ] ] Recursive dialects are very easy to validate with PARSE but very difficult to evaluate. (Stacks can be helpful here.) REBOL has very poor integration with many popular technologies, particularly XML. I suspect this is partly arrogance, because the REBOL BLOCK! datatype can do almost everything XML can do. However, the real world has XML in it. No Unicode. Thanks to AltMe, REBOL's user community is very insular. I can understand why they want to use AltMe. It's written in REBOL and shows off its strengths. Unfortunately it also puts them off on their own little island.

即将到来的REBOL 3有望解决许多这些问题，除了最后一个。

C++

模板的语法 钻石传承问题 现代语言所拥有的标准库过多/缺乏(尽管boost也很接近)。 iostream IOStreams周围使用的语法

Python

空格是有意义的(有时) 强调关键词 有限的线程支持(至少目前) 用self代替this 空格是有意义的(有时)

ColdFusion

大型Flash表单的编译时间。 动态变量类型(有时我讨厌它们) CFScript缺乏特性。 CFTable(永远不能正确显示)。 CFChart中缺少图表类型。 完全缺乏NTLM支持(企业就绪-是的) cfc中的低能变量作用域 没有一个真正的NULL的概念-你的变量只是消失! 没有办法测试某些东西的存在(比如作用域，只是它们内部的成员)

VB6

仅Windows。 不再支持。 数组可以从任何数字开始，而不是全部归一化为0。 已编译的应用程序依赖于许多dll才能正常运行。 许多复杂的控件(如浏览器控件或复杂的代码段)在运行未编译的代码时往往会破坏IDE，但在编译后却可以正常工作。

我是在冒险，因为我不能全职使用它，但无论如何我会尝试一下!

Perl 6

func("frew") != func ("frew") It annoys me, but there is good reason for it. In Perl 5 print (5 + 6) * 10 still gets me every now and then It may be easier to parse than Perl 5 in a lot of places, but it still kills my editor sometimes It still has a lot of the line noise Perl 5 which scares a lot of people. That means it's harder to get them excited etc. There are no libraries yet. This will be a non issue if Perl 6 does indeed end up supporting Perl 5, but that may be a burden not worth bearing. There's no REPL, or what rubyists would call irb. A solid interactive Perl 6 with tab completion, color coding, etc, would make using and learning it so much nicer. Currently the documentation is basically the English spec. Not exactly an easy read. I know it's a stupid cliche, but it's not out yet! (I am allowed to complain because I am helping :-P)

前三点是语言;剩下的并不是语言本身，而是它还没有问世的事实。