Python:

No standard GUI toolkit (the community goes round and round about this but never seems to settle on anything). The evolution of tools and methods to distribute and install Python apps and libraries has been, well, rocky. (Although lately this seems to be moving closer to getting fixed.) CPython is still slow as interpreters go (although PyPy is looking pretty good these days, if it becomes the "standard" Python this problem goes away). You can't subclass built-in classes (e.g., list and dict) without overriding a lot of methods, even if all you want to do is a simple hook into an event (e.g., to hook into an item being added to or removed from the list, you need to override delitem, append, extend, insert, pop, and remove--there's no subclassable "change" event notification, nor any "protected" methods that factor out common code used by all the above methods). Up until virtualenv was invented, keeping separate Python environments for different purposes on one machine was a real pain.

Haskell。

默认情况下导入Prelude。 类型类的范围是通用的。 模块不是一流的。 类型不能依赖于值。 单子不统一Functor。

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.

Ruby有许多与速度相关的缺陷，但我并不讨厌它们。它也有社区传福音过度的缺陷，但这并没有真正困扰我。以下是我最讨厌的:

Closures (blocks) have 4 different creation syntaxes, and none of them are optimal. The elegant syntax is incomplete and ambiguous with hashes, and the full syntax is ugly. The community tends to be against real documentation, favoring ‘read the code’. I find this childish and lazy. Metaprogramming abuse, particularly in libraries, makes bugs a nightmare to track down. On a related note, pervasive metaprogramming makes a comprehensive IDE difficult, if not impossible, to make. The way block passing to functions is done is silly. There is no reason blocks should be passed outside the parameter list, or have odd special syntax to access (yield). I am of the opinion that blocks should have been given a less ambiguous syntax (or hashes could have used different delimiters; perhaps <> rather than {}), and passing as parameters to methods should have been just like all other parameters. object.method(1, {|a| a.bar}, "blah") These oddities, like the block must be the last parameter passed and passing more than one block is different with longer syntax, really annoy me.

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)

Ruby:

重要的空白。对于解释器，行尾=语句的结束，除非看起来语句应该继续(或者显式转义换行符)。 慢 在线文档不如Python的好(为了辩护，Python的很棒) 我刚才提到慢了吗?