Lua:

The built-in error system is absolutely horrendous You can implement a try-catch system by modifying the Lua interpreter; but it has no compatibility with the errors that are thrown by the built in functions. The fact they have __newindex instead of __setindex as the setter ... and __newindex is only fired when the key doesn't already exist. If it does, no metamethod is called at all. No good type comparison system. There's the type() function but it only handles the basic types (all tables are tables). It really needs to have a metamethod for type comparisons. I've implemented this before with an 'is' operator and a __type metamethod and it works really nicely. It's a bitch to define new keywords. You can do it, but the code inside Lua isn't well documented so it's kind of trial and error to find out how to get the result you want. This is a major issue when you want to implement the things I mentioned above yourself (not so much __setindex though, that's an easy modification). I can't use it in a web browser. Yeah not really a problem with the language itself, but damn, would I love to be able to use Lua instead of Javascript... :)

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)

F#

Type inference is limited. It propagates forward only. F# won't try to infer an object type based on the methods and properties used: you'll get "lookup of indeterminate object type" errors when it doesn't have a clue. One cannot mix floats and ints: 1 + 2.3 is a type error. It's a little awkward to have to create a builder object in order to define a monad or computation expression. In Haskell or Scala, you can define the monad operations directly on the monadic object. Though the #light syntax is preferred, the indentation rules are sometimes not very intuitive or become cumbersome.

Common Lisp:

关键词往往太啰嗦。 库支持是可怜的。 在希望更严格地处理内存的操作系统中不能很好地工作。 没有与操作系统交互的良好工具。 “循环”功能没有很好地定义，当然看起来也不像Lispy。

再给c++投一票…仍然是我最喜欢的语言，有几个亲密的追随者——C和Python。以下是我目前最讨厌的名单，排名不分先后:

Plethora of integer types inherited from C - way too many problems caused by signed vs. unsigned mistakes Copy constructors and assignment operators - why can't the compiler create one from the other automatically? Variable argument madness - va_list just doesn't work with objects and I'm so sick of problems created with sprintf(), snprintf(), vsnprintf(), and all of their relatives. Template implementation is required to be fully visible at compile time - I'm thinking of the lack of "export" implementations or at least usable ones Lack of support for properties - I want to have a read-only member like "a.x" that can be read publicly and only assigned internally. I really hate the "val=obj.getX()" and "obj.setX(val)". I really want properties with access control and a consistent syntax.

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?