.NET框架(库)

嵌套类型很少使用(例如MessageBoxButton应该是MessageBox.Button) 可变结构体(Rect, Point) 系统名称空间中有太多东西 太多不同的平等概念(对象。等于,对象。ReferenceEquals, operator ==， operator !=， IComparable.CompareTo() == 0) 数组的成员是可变的，但长度是不变的。

还有一点:

XmlSerialization不适用于不可变类型

Common Lisp

conditions aren't classes (since classes came later), even though their interface is almost identical some of the names are just weird, e.g., flet / labels (only difference: scope), and defvar / defparameter (only difference: behavior when already defined), or any of the bit-twiddling functions (dpb, ldb, etc.) packages are ... really hard to get right -- every time I think I understand them, they don't do what I want built-in data structures and functions aren't as generic as they could be (e.g., why can't I define my own hash function portably?) multiple namespaces for functions, variables, etc. (I'm not opposed to this in principle, but CL made it too complex; Norvig has said he can't tell from the spec but there appear to be at least 7 namespaces)

JavaScript:

The Object prototype can be modified. Every single object in your program gets new properties, and something probably breaks. All objects are hash maps, but it's difficult to safely use them as such. In particular, if one of your keys happens to be __proto__, you're in trouble. No object closure at function reference time. In fact, no object closure at all -- instead, this is set whenever a function is called with object notation or the new operator. Results in much confusion, particularly when creating event callbacks, because this isn't set to what the programmer expects. Corollary: calling a function without object notation or the new operator results in this being set equal to the global object, resulting in much breakage. Addition operator overloaded to also perform string concatenation, despite the two operations being fundamentally different. Results in pain when a value you expect to be a number is in fact a string. == and != operators perform type coercion. Comparisons between different types involve a list of rules that no mortal can remember in full. This is mitigated by the existence of === and !== operators. Both null and undefined exist, with subtly different, yet redundant meanings. Why? Weird syntax for setting up prototype chains. parseInt(s) expects a C-style number, so treats values with leading zeroes as octal, etc. You can at least parseInt(s, 10) but the default behaviour is confusing. No block scope. Can declare the same variable more than once. Can use a variable without declaring it, in which case it's global and probably breaks your program. with { }. Really difficult to document with JavaDoc like tools.

objective - c

1)没有命名空间，只有手动命名约定——我不介意在类分离方面，但我确实怀念能够在一行命名空间中导入所有类定义(如import com.me.somelibrary.*)。

2)库在像RegEx支持这样的重要领域仍然存在一些漏洞。

3)属性语法有点笨拙，需要三行(在两个单独的文件中)来声明一个属性。

4)我喜欢保留/释放模式，但它比应该的更容易释放一个引用，然后意外地使用它。

5)虽然不是真正的语言特性，但Xcode与Objective-C的使用是如此交织在一起，我不禁想到这方面……基本上自动补全，是很可疑的。它更像是一个奖励你找到你想要的东西的系统，然后把它作为一个选择。但我想我从来都不喜欢自动补全引擎。

BrainF * ck

你的亮点是图灵完备?!我可以在Perl正则表达式中做更多的事情! 缺少对象。来吧,人!就像，你好… 没有网络库。我只想刮一个网页，天哪。 没有一级函数。恭喜你——你可以同情你的Java朋友了。 一个无限的磁带存储，没有其他。这是如此的矫情，我们可能还在写Lisp。

Python:

1) line continuation syntax: "...\" works, but "...\ " does not, and that trailing space is generally invisible, without unusual eol-marking by editer. 2) a bare 'raise' is invisible in the stack trace, as the stack trace looks like the previous raised exception. 3) slow 4) poor integration into web-servers (mod_python: dead, mod_wsgi: limited scope of operation). This is complicated by 3], requiring daemonization or some sort of memory-persistance to perform well. 5) overly tolerant of mixed tabs and spaces, allowing changes to control flow to sometimes remain hidden. (maybe fixed in recent versions)