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。

C#

Reference types are nullable by default; in-language null keyword is untyped. Lack of discriminated unions Exceptions as default, non-exceptional error handling method - there's not much of an alternative. archaic switch statement syntax and limitations Needless distinction between constructors + static methods Static methods can't be part of an interface Lack of by-shape interface implementation rather than explicit interface implementation - leading to numerous language design hacks such as the linq query syntax, foreach, collection & object initializers -- none of which can be flexibly reused. For example, the object initializer syntax may be nice, but plays poorly with immutable objects. Cannot inherit "interface" of a class independently of implementation - leading to code duplications and overarchitected code that provides interfaces, abstract base classes, a few common implementations, and no way to pick and choose the bits of each to use. Also; leads to too many code that's tightly coupled to a particular implementation since it's common to explicitly refer to the implementation type rather than an interface. Cannot multiply inherit via composition since a classes "interface" is tightly coupled to it's implementation; effectively lack of mixins. The above limitations of interfaces lead to a proliferation of virtually identical interfaces that don't overlap naturally in any kind of type hierarchy. IComparable vs. IEquatable vs. IComparable<T> vs object.Equals vs. operator == etc. etc. By extension, making a custom type that satisfies all these things is a lot more work than necessary (in particular for collection classes). Obviously, the language designers realize this, hence the various workarounds for things like linq, foreach and collection initializers which work by-shape rather than by-interface. Redundant use of parentheses and braces rather than layout-is-structure. Return values can be ignored, limiting the effectiveness of type inference. Enums aren't a normal type and can't have methods. Also, enum values aren't typesafe and may be initialized to 0 despite not having a 0 value. Mixing metaphors by lumping flag and non-flag enums together. Lack of proper value type support. Value types can't be inherited, have different constructor semantics, and perform poorly due to CLR limitations. Also, confusing semantics regarding value types: some values are really values (and can't be modified), and others are really non-aliased, non-null references (variables). This gets particularly confusing with regards to the next issue: Semantic distinction between fields and properties, particularly in conjunction with lack of mutability modifier (ala C++'s const) Can't specialize generics Cannot provide default generic type parameters (e.g. factory generics) lack of typedef makes generics a pain to use (using is a limited but good-to-know substitute!) Can't genericize over things other than types (e.g. functions, plain values, or names). This means you can't do something like make a generic implementation of a dependancy property leading to, well, nasty implementations of things like dependancy properties and the overuse of code-snippets and poorly readable code as a result. Limited capability to specify generic type requirements e.g. generic sum method that takes both int, double and a bigint (without tricky and often slow hacks). An interface method implementation or virtual method override cannot return a more specific type or accept a more general type; i.e. limited co/contravariance support even in C# 4.

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。

Ruby

无类型推断 方法/函数不是一级对象 变量的范围不是词法的，尽管块变量的范围是词法的 Def内部的Def super和super()的区别

Perl

我喜欢这门语言，我不想添加已经被使用过的东西，但还没有人提到过这一点，所以我就把它扔到锅上。当我使用这个特性时，我发现这是我一生中最可怕的经历(而且我用过汇编语言):

write()和format()函数。

它们的语法是最糟糕、最丑陋、最可怕的，但是它们并没有提供比printf()更好的功能更多的功能。任何人都不应该尝试使用这两个函数进行任何输出，因为它们有多糟糕。

我相信有人会不同意，但是当我研究它们，希望它们能解决我的问题时，我发现它们是一个“痛苦的世界”(引用Big Lebowski的话)，我希望Perl6已经消除了它们，或者更好的是完全重写它们，使它们在某种程度上更可用和有用。

我是在冒险，因为我不能全职使用它，但无论如何我会尝试一下!

Perl 6

func("frew") != func ("frew") It annoys me, but there is good reason for it. In Perl 5 print (5 + 6) * 10 still gets me every now and then It may be easier to parse than Perl 5 in a lot of places, but it still kills my editor sometimes It still has a lot of the line noise Perl 5 which scares a lot of people. That means it's harder to get them excited etc. There are no libraries yet. This will be a non issue if Perl 6 does indeed end up supporting Perl 5, but that may be a burden not worth bearing. There's no REPL, or what rubyists would call irb. A solid interactive Perl 6 with tab completion, color coding, etc, would make using and learning it so much nicer. Currently the documentation is basically the English spec. Not exactly an easy read. I know it's a stupid cliche, but it's not out yet! (I am allowed to complain because I am helping :-P)

前三点是语言;剩下的并不是语言本身，而是它还没有问世的事实。