Perl

Mixed use of sigils my @array = ( 1, 2, 3 ); my $array = [ 4, 5, 6 ]; my $one = $array[0]; # not @array[0], you would get the length instead my $four = $array->[0]; # definitely not $array[0] my( $two, $three ) = @array[1,2]; my( $five, $six ) = @$array[1,2]; # coerce to array first my $length_a = @array; my $length_s = @$array; my $ref_a = \@array; my $ref_s = $array; For example none of these are the same: $array[0] # First element of @array @array[0] # Slice of only the First element of @array %array[0] # Syntax error $array->[0] # First element of an array referenced by $array @array->[0] # Deprecated first element of @array %array->[0] # Invalid reference $array{0} # Element of %array referenced by string '0' @array{0} # Slice of only one element of %array referenced by string '0' %array{0} # Syntax error $array->{0} # Element of a hash referenced by $array @array->{0} # Invalid reference %array->{0} # Deprecated Element of %array referenced by string '0' In Perl6 it is written: my @array = ( 1, 2, 3 ); my $array = [ 4, 5, 6 ]; my $one = @array[0]; my $four = $array[0]; # $array.[0] my( $two, $three ) = @array[1,2]; my( $five, $six ) = $array[1,2]; my $length_a = @array.length; my $length_s = $array.length; my $ref_a = @array; my $ref_s = $array; Lack of true OO package my_object; # fake constructor sub new{ bless {}, $_[0] } # fake properties/attributes sub var_a{ my $self = shift @_; $self->{'var_a'} = $_[0] if @_; $self->{'var_a'} } In Perl6 it is written: class Dog is Mammal { has $.name = "fido"; has $.tail is rw; has @.legs; has $!brain; method doit ($a, $b, $c) { ... } ... } Poorly designed regex features /(?=regexp)/; # look ahead /(?<=fixed-regexp)/; # look behind /(?!regexp)/; # negative look ahead /(?<!fixed-regexp)/; # negative look behind /(?>regexp)/; # independent sub expression /(capture)/; # simple capture /(?:don't capture)/; # non-capturing group /(?<name>regexp)/; # named capture /[A-Z]/; # character class /[^A-Z]/; # inverted character class # '-' would have to be the first or last element in # the character class to include it in the match # without escaping it /(?(condition)yes-regexp)/; /(?(condition)yes-regexp|no-regexp)/; /\b\s*\b/; # almost matches Perl6's <ws> /(?{ print "hi\n" })/; # run perl code In Perl6 it is written: / <?before pattern> /; # lookahead / <?after pattern> /; # lookbehind / regexp :: pattern /; # backtracking control / ( capture ) /; # simple capture / $<name>=[ regexp ] /; # named capture / [ don't capture ] /; # non-capturing group / <[A..Z]> /; # character class / <-[A..Z]> /; # inverted character class # you don't generally use '.' in a character class anyway / <ws> /; # Smart whitespace match / { say 'hi' } /; # run perl code Lack of multiple dispatch sub f( int $i ){ ... } # err sub f( float $i ){ ... } # err sub f($){ ... } # occasionally useful In Perl6 it is written: multi sub f( int $i ){ ... } multi sub f( num $i ){ ... } multi sub f( $i where $i == 0 ){ ... } multi sub f( $i ){ ... } # everything else Poor Operator overloading package my_object; use overload '+' => \&add, ... ; In Perl6 it is written: multi sub infix:<+> (Us $us, Them $them) | (Them $them, Us $us) { ... }

PHP:

荒谬的assert()函数…它对里面的代码运行eval() ?>标签删除了它后面的换行符?! 奇怪的数字字符串处理(尝试将它们作为数组键) 令人痛苦的unicode支持似乎将不再被PHP 6解决 入门成本低意味着95%的人给PHP程序员起了一个可怕的名字——试图在这5%中找到一个人来雇佣是疯狂的。

C#

c#最让人讨厌的是:

(1)事件具有对所有侦听器的强引用，从而防止了侦听事件的任何东西的垃圾收集。如果你想看到这造成的问题，只需在网上搜索所有试图通过创建某种“弱引用事件处理程序”来解决问题的人。

(2)在调用一个事件之前，需要检查它是否等于null，这似乎应该由语言来处理。

(3) XML序列化器无法读取/写入XML文件中的注释。在手工修改XML文件和用c#编写的工具修改XML文件的环境中，情况并不好。可以通过使用原始的XmlDocument来解决，但如果能够将其抽象到一个类中会更好。

(4)构建过程不允许您直接访问xsd文件之类的东西，相反，您需要一个中间步骤，即创建一个c#部分类。这也会导致XAML文件出现问题，有时需要重新构建两次才能使更改正确地通过。

(5)不支持CPU intrinsic，如MMX和SSE 1,2,3,4，因此这些有价值的CPU特性在运行c#应用程序时无法使用。

其他没有进入我的前5名:

(6)不能将字段标记为属性，所有属性必须从一开始就显式地实现:

目前有:

public class MyClass {
    private int someInt;

    public int SomeInt {
        get {
                return someInt;
        }
        set {
                someInt = value;
        }
    }
}

想

public class MyClass {
    [IsProperty(public, get, set)]
    private int someInt;
}

(7)不支持多个返回值，例如:

public int, string, double MyFunction()
{
    ....
    return x,y,z;
}


public void TestMyFunction()
{
    int x, string y, double z = MyFunction();
}

(8)不支持协变返回类型

我对泛型实现有一些不满，但我就此打住。我认为c#是一种很棒的语言，可以完成所有的GUI、网络和配置管道，并且是我的首选语言，可以以一种可以长期支持的方式快速启动和运行。

Quenya

• Community is too small. It's next to impossible to get a good language-immersion program going when there's no easy to find another speaker nearby. • Irregular verbs. Yes, I know English and Spanish mentioned them, too, but Quenya was invented. Why does there still need to be irregular verbs? • No Unicode support. I have to have three different Tengwar fonts on my computer before I can read most messages, and several of them are poorly kerned. This wouldn't really be a huge issue given the existence of a Romanized transcription, but Tengwar is so beautiful, you don't not want to use it. • Not all concepts can be easily referenced in Quenya, leading to annoying circumlocutions, or resorting to Sindarin, Númenórean, or (Manwë save me) Klingon to get my point across.

Java

已检查的异常 类型擦除 缺少操作符重载(例如BigInteger/BigDecimal) 缺少regexp/date/duration /复杂文字 对不可变性的支持很差

C#

Cannot create a reference (var &t = struct) No local scope destructors (IDispose comes close but its not the same) ToString, i almost dislike that every object has it but it turns out i dislike everything using it like string.format does. I rather have things that accepts a certain type (like ints, floats, text, chars only). So instead of passing in any object i need to pass in something with a implicit typecast or interface. I ended up writing something like this to safely escape text for html which worked great. Cannot use a virtual typecast (blah)obj; does not work if obj does not inherit/has an interface of blah. Simple workaround is to supply an interface with a convert function. Has no local creation. Instead of writing var o = new Item(); i would like to write (something like) Item o() (with an automatic dispose if it has one).