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.

我觉得最喜欢的语言是不可能选择的。动态类型和静态类型不能进行比较，所以我只列出我使用的是哪一种类型

C++:

Template metaprogramming syntax is ugly. An implicit ::value would make it much more concise ->. Why can't the compiler figure out that I'm doing a ptr.thing and just do -> for me? I hate whitespace. So the whole vector<vector<int>> has to be vector<vector<int> > makes me get the jitters and then I can't focus whenever I see that line of code and I end up trying to figure out a way to use int[][] or something Macros. I personally love the concept of macros. But with C++, I that the system is a hack I'm a hater of ;

Python:

字符串是不可变的。这样我就不能用string[4]="b" 通过引用隐式复制列表。哪个泄漏到[[0]*width]*height问题 缺少尾递归(每当我输入错误递归函数时，我必须安装IDLE以避免吐出1000条错误消息) 字典键不接受列表/字典 缺乏深度范围。当我做一个列表推导时，我不希望其中的变量影响到外部作用域

Ruby:

太慢了 自负的群体 这不是闲谈 在nil上调用方法时出错，而不是返回nil à la Objective C 非线程

MEL(玛雅表达语言):

Single dimensions arrays: Forcing me to manually sync two or more lists, or use delimited strings to simulate more complex data structures. Naturally, they're immutable too. Single threaded and slow: Causing the entire Maya application to hang while it completes a task. Bonus points for not being able to kill long operations, instead having to close and re-open Maya. Script sourcing paths aren't recursive: Meaning every directory you want to store scripts in must all be added to the script path. No namespaces: Forcing the inconsistent use of naming conventions to make sure global procedures don't collide. Modal commands: Each command is modal, meaning the Create, Modify, and Query operations are all handled by setting flags. This also forced the developers to cause most of the commands to return arrays Inconsistent command style: Most array commands actually return arrays, but the Tokenize command has to take an array as a reference which it then populates, rather than spitting out an array. This among other inconsistencies.

这些以及其他几个原因是AutoDesk采用Python作为次要脚本语言的原因，这带来了其他一些令人讨厌的因素:

并不是所有的MEL命令都受支持:大多数都受支持，但有时您会发现自己不得不使用MEL()函数来执行一些任意代码。更糟糕的是，你不得不对它进行所有烦人的逃避。 继承了模态命令风格:必须使用相同的create=True, query=True, edit=True的东西。

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。

Oracle SQL

DUAL表。 不能通过别名分组。 我永远记不住分析函数的语法，所以我忘记/懒得使用它们。 缺少组合的LIKE和IN条件运算符。(不过，在10g之后，有一个REGEX_LIKE操作符可以做到这一点。) 笨拙的连接语法。

SQL并不是我最喜欢的语言，但它是我每天使用的三大语言之一。可能还有更多的项目，但这些是我脑海中最重要的。

我有一大堆SQL*PLUS的问题。我写了一个Perl的替代品，从命令行做我想做的，我使用sql。Emacs中的el用于交互式SQL会话。这些工具可以帮助我解决SQL*PLUS问题。

说到这里:

Perl

"Only perl can parse Perl." (But this is mostly an issue in syntax highlighting, which I don't prefer to use much anymore for any language.) I'm sometimes surprised by "the simple (but occasionally surprising) rule...: It looks like a function, therefore it is function, and precedence doesn't matter." (From perlfunc(1)) Dereferencing complex data structures can be confusing at times. I can't decide if this is a true flaw in Perl or just a consequence of having really powerful data structure facilities. Either way, I can normally get it right by taking a few minutes to think about what I'm doing. No option to cause system calls to raise their errors like the DBI module. (Thanks to brian d foy, I now know the autodie module on CPAN does this, but I'd like it built-in.) Warnings and strictures not enabled by default in scripts. (The -e option would turn them off for command line use.)

同样，肯定还有更多的事情，但这些是我最近注意到的问题。我还要加上=over and =back和古怪的L<…>语法在POD中，但也许那应该是一个单独的列表。

现在来看看三连冠:

康壳牌

Sourcing a file with arguments replaces the values of the parent script's arguments. (Executing . file arg1 puts arg1 in $1.) ksh is not an ideal interactive shell and defaults to vi key-bindings, rather than emacs. (My solution is to use bash for interactive shells.) Common utilities (such as grep) are implemented differently across different platforms thereby preventing perfect portability. Some useful commands need to be installed on some platforms and are part of the OS core on others. The syntax for conditionals is overly heavy. (if [ ... ]; then ... fi) Although it is Turing Complete, you are eventually going to want to move up to a more expressive language like Perl.

第4个问题的一个解决方案是习惯短路评估:

[ ... ] && ...