Perl代表了一种可怕的语言。

No "public" or "private" or "protected" declarations/definitions. The "my $variable_name;" does not declare a global outside of a subroutine. The "my $variable_name;" gets accessed by subroutines but "use strict;" or other "use " creates warnings. Function prototypes end up unexplained, undemonstrated, unwanted, or some other excuse. Overzealous symbol use ends up "cool and quick" when reading globs of symbols. When one gets hot they like to stay hot, and need nothing to cool them. After a week of Perl, I end up unable to write a function and prototype it. What exactly is a module and does it actually NEED a ".pm" extension? If you want to create a public variable and access it from inside a subroutine, how do you accomplish this without creating a warning? Where do you find some neat scripts that teach one some neat Perl?

C#

当被枚举的集合中的对象发生变化时，foreach命令弹出， UI控件吐出假人，因为它们在错误的线程上访问。当然是所有的调度员。调用可以移动到CLR管道， PInvoke，编组等， 我浪费了两年时间学习远程遥控， 它没有露比性感。

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:

[ ... ] && ...

Python:

You usually have the entry point of the program at the end of the file. (Because if it calls any function defined in the module, it has to occur after those functions in the sources.) I hate it when you have to spend time looking for the entry point of a program, so I always have a simple main.py file with: def main(): ... if __name__ == '__main__': main() When an exception is raised, it can only be catched by the main thread. Or something like that. Destructors are quite useless, because when written in Python they may break garbage collection IIRC. I've never figured out how relative imports work in Python 2. I'd like to see more collections in the standard library. For example: linked lists, thread-safe collections, ...

C#

它是一种很棒的语言，特别是在LINQ中，但是与c++相比泛型支持较差。它有如此多的潜力，但目前的实现只对强类型集合和类似的琐碎事情有用。下面举几个例子:

A generic argument cannot be restricted to enums (only classes or structs). A generic argument cannot be a static class. Why? This seems like a completely artifical restriction. You cannot specify that a generic type must have a constructor with a certain signature because you cannot have constructors on interfaces. Why not? It's just another method with the special name ".ctor". Similarly, you cannot specify that a generic type must have a static method, because those also cannot be declared on interface. Something like static T Parse(string s) would often come in useful. The compiler is too eager in prohibiting some casts which the programmer knows would actually work, so they require uglyness like (TheRealType)(object)value No covariance, eg. IList<string> cannot be converted to IList<object>, even though string[] can be converted to object[]. (Microsoft might be fixing this in C# 4.0, though.)

ActionScript / AS3

没有抽象类 没有私有构造函数(所以单例是一种hack) FP10之前没有类型化数组 Flash IDE中的编译/发布时间慢得离谱 内置函数(例如Math)的性能较慢

除此之外，它实际上是一种很好的语言——与流行的观点相反，它比JavaScript好得多，比PHP之类的语言好一百万倍。