最近Stack Overflow上有一群讨厌perl的人,所以我想我应该把我的“关于你最喜欢的语言你讨厌的五件事”的问题带到Stack Overflow上。拿你最喜欢的语言来说,告诉我你讨厌它的五件事。这些可能只是让你烦恼的事情,承认的设计缺陷,公认的性能问题,或任何其他类别。你只需要讨厌它,它必须是你最喜欢的语言。

不要拿它和其他语言比较,也不要谈论你已经讨厌的语言。不要用你最喜欢的语言谈论你喜欢的事情。我只是想听到你讨厌但能容忍的东西,这样你就可以使用所有其他的东西,我想听到你希望别人使用的语言。

每当有人试图把他们最喜欢的语言强加给我时,我就会问这个问题,有时是面试问题。如果有人找不出他最喜欢的工具的5个缺点,那他对它还不够了解,不能提倡它,也不能利用它赚大钱。他还没有在足够多的不同情况下使用它来充分探索它。他把它作为一种文化或宗教来倡导,这意味着如果我不选择他最喜欢的技术,我就错了。

我不在乎你用什么语言。不想使用特定的语言?那就不要。你通过尽职调查做出了明智的选择,但仍然没有使用它?好吧。有时正确的答案是“你有一个强大的编程团队,有良好的实践和丰富的Bar经验。改成Foo是愚蠢的。”


This is a good question for code reviews too. People who really know a codebase will have all sorts of suggestions for it, and those who don't know it so well have non-specific complaints. I ask things like "If you could start over on this project, what would you do differently?" In this fantasy land, users and programmers get to complain about anything and everything they don't like. "I want a better interface", "I want to separate the model from the view", "I'd use this module instead of this other one", "I'd rename this set of methods", or whatever they really don't like about the current situation. That's how I get a handle on how much a particular developer knows about the codebase. It's also a clue about how much of the programmer's ego is tied up in what he's telling me.

憎恨并不是衡量人们了解多少的唯一尺度,但我发现它是一个相当不错的尺度。他们讨厌的事情也让我知道他们对这个话题的思考有多好。


当前回答

按最讨厌到最不讨厌的顺序排列。

1.) Backwards compatibility police. Yes backcompat is a strength but Perl 5 takes it too far. Now we don't really even get new features in our language without having to enable them explicitly. I'm much prefer the inverse, if a new feature causes a problem let me disable it or enforce old behavior. e.g. perl 5.10 added say I'd rather have no feature 'say' if I have my own say implemented than have to put use feature 'say'; or use 5.010; also if 5.8 worked but 5.10 didn't. I'd rather have use 5.008; to restrict my code to only use features available up to and including 5.8 if no use version; was defined then it should be defaulted to whatever version you're running, and a recommended practice of not to restrict it unless you have to.

2)。过度的样板。

#!/usr/bin/perl
use strict;
use warnings;
use utf8;
use autodie;
use English '-no_match_vars';
use 5.010;
package Package::Name;

BEGIN {
    Package::Name::VERSION = 0.1;
}

sub somesub {
    my $self = shift;
    my ( $param1, $param2 ) = @_;
}
1;

现在你可以开始编码了。这不会因为第一条而改变。当然也有一些捷径,比如使用common::sense;或者使用modern::perl;这将缩短上面的内容,你可能需要一些稍微不同的模块或pragma。但因为第一条,我们永远无法把它降低到。

#!/usr/bin/perl
package Package::Name 0.01;

sub somesub ( $param1, $param2 ) {
}

一些模块正在帮助这一点,在5.0.12中有新的包版本,它完全允许这种语法,尽管我认为它需要使用5.012;首先,和Method::签名,但它永远不会完全解决,(在语言)。

3)。糟糕的变量选择

吸吸文件

#!/usr/bin/perl
use strict;
use warnings;
open my $fh, "< foo" or die $!;
local $/; # enable localized slurp mode
my $content = <$fh>;
close $fh;

WTF是$!和美元/ ?重写为易读。

#!/usr/bin/perl
use strict;
use warnings;
use English '-no_match_vars';
open my $fh, "< foo" or die $ERRNO;
local $INPUT_RECORD_SEPARATOR; # enable localized slurp mode
my $content = <$fh>;
close $fh;

不要忘记,如果您不想受到性能影响,'-no_match_vars'必须存在。

不直接创建匿名标量怎么样?

#!/usr/bin/perl
my $scalar_ref = \do{ my $anon_scalar };

他们就不能想出点什么办法吗?

#!/usr/bin/perl
my $scalar_ref = <>;

哦,perl是线程不友好的,因为所有的变量(包括特殊的变量)默认是全局的。至少现在你可以使用我的$_;对其词法作用域,并对其他词使用local。

4.)非常难看的语法

MooseX::Declare是一个更好的语法。我也希望->被替换为。(个人喜好不太重要)

5)。太多的TIMTOWTDI或太多的最佳实践似乎你必须读3-5本书才能弄清楚你应该如何做事情。

6)。以前的(不再适用)。Un-sane版本。5.10.0有新功能5.10.1的新功能没有设定时间,直到下一个版本。现在是每年一次的特性发布,每季度更新一次。

7)。象牙塔视角。社区问题,似乎是许多开发者想要设置更高的准入门槛,并认为可以不尊重n00b(或任何不同意他们的人)。

8)。疯狂的版本号/字符串Perl有浮点版本号,它们很难看。开发人员不知道并不是所有的下游处理版本比较的方式都是一样的。不是语言问题

0.012 # simple
5.012001 # semantic 
4.101900 # time based + version (for multiple versions in a day)
0.035_002 # prerelease

所有有效版本的perl..我们就不能用…

0.12 # simple
5.12.1 # semantic
20100713 # time based (just use the date and be careful not to need to release more than 1 a day)
0.35-beta2 # prerelease

除了

9)。升级后没有明显的方法重新安装所有XS模块

其他回答

我知道我迟到了,但恨是永恒的!

Java

Runtime.exec(). So, if I don't manually clear the STDOUT and STDERR buffers, my code will hang? Wow. Die, plz. Null Pointer Exceptions. Responsible programming means I have to treat most objects like they're unexploded bombs, which is kind of a pisser in an object-oriented language. And when the inevitable happens I kinda need to know which object blew up in my face, but Java apparently feels telling me would be cheating. File I/O. Why do I have to jump through this many hoops to read a dang text file? And when copying files, I have to funnel the source file into my code and manually handle the output byte buffer? You're serious? Primitives vs. Primitive Wrappers. Note that Java now has a number of features that allow you to treat primitives and their wrapper objects as interchangeable in some places, but not in others; don't worry, the compiler will let you know which is which. This feels like a hack to work around a fundamentally broketastic design decision. And it is. (EDIT: Actually, the compiler is a much crappier safety net than I thought, particular when doing equality checks. If `a` and `b` are integers, `a == b` is guaranteed to behave as expected only if at least one of them is of type `int`. If they're both type `Integer`, then that statement will do what you think only if the two numbers are between -128 and 127. `Integer a = 1000; Integer b = 1000; return a == b;` will return `false`. Really.) XML. I have this dirt-simple little XML file I need to create and I have to do what?

c#(好吧,我猜一部分是VisualStudio IDE):

No covariance (yet), like Class<D> cannot be used in place of Class<B> even though type D derives from type B. Graphic designers don't support generic based inheritance (or inheritance from abstract classes), even though the inheritance itself works just fine if you work around the designer problems by adding extra inheritance levels just so designers always see concrete non-generic variants of your code. No constructor inheritance No constructors in where clauses of generic type parameters VisualStudio seems to have a tendency to mysteriously check out files (like project files and/or unit test definitions) when opening a solution, even though the files do not seem to actually get altered.

如果你明天再问我,可能会有不同的名单。即使协方差和设计师的麻烦将在我的前5名,直到他们被解决(随着方差添加到c# 4.0,这似乎已经发生了至少一个…)

我使用Java,我最大的不满是字符串操作的低效率。当你使用+运算符时。说真的,难道编译器不能计算出我添加了多少字符串,然后在后台为我生成StringBuffer的东西吗?

通常,使用+的代码比StringBuffers操作序列更具可读性。

另外,我讨厌本机数组和集合框架之间的冗余。. toarray()的语法极其丑陋。

c# / .net:

Classes should be sealed by default There should be no lock statement - instead, you should have specific locking objects, and there should be methods such as Acquire which return disposable lock tokens. Corollary: there shouldn't be a monitor for every object. GetHashCode() and Equals() shouldn't be in System.Object - not everything's suitable for hashing. Instead, have an IdentityComparer which does the same thing, and keep the IComparer<T>, IComparable<T>, IEqualityComparer<T> and IEquatable<T> interfaces for custom comparisons. Poor support for immutability Poor way of discovering extension methods - it should be a much more conscious decision than just the fact that I'm using a namespace.

这些都是我想出来的,明天问我,我会想出一个不同的5个:)

Oracle SQL

DUAL表。 不能通过别名分组。 我永远记不住分析函数的语法,所以我忘记/懒得使用它们。 缺少组合的LIKE和IN条件运算符。(不过,在10g之后,有一个REGEX_LIKE操作符可以做到这一点。) 笨拙的连接语法。

SQL并不是我最喜欢的语言,但它是我每天使用的三大语言之一。可能还有更多的项目,但这些是我脑海中最重要的。

我有一大堆SQL*PLUS的问题。我写了一个Perl的替代品,从命令行做我想做的,我使用sql。Emacs中的el用于交互式SQL会话。这些工具可以帮助我解决SQL*PLUS问题。


说到这里:

Perl

"Only perl can parse Perl." (But this is mostly an issue in syntax highlighting, which I don't prefer to use much anymore for any language.) I'm sometimes surprised by "the simple (but occasionally surprising) rule...: It looks like a function, therefore it is function, and precedence doesn't matter." (From perlfunc(1)) Dereferencing complex data structures can be confusing at times. I can't decide if this is a true flaw in Perl or just a consequence of having really powerful data structure facilities. Either way, I can normally get it right by taking a few minutes to think about what I'm doing. No option to cause system calls to raise their errors like the DBI module. (Thanks to brian d foy, I now know the autodie module on CPAN does this, but I'd like it built-in.) Warnings and strictures not enabled by default in scripts. (The -e option would turn them off for command line use.)

同样,肯定还有更多的事情,但这些是我最近注意到的问题。我还要加上=over and =back和古怪的L<…>语法在POD中,但也许那应该是一个单独的列表。


现在来看看三连冠:

康壳牌

Sourcing a file with arguments replaces the values of the parent script's arguments. (Executing . file arg1 puts arg1 in $1.) ksh is not an ideal interactive shell and defaults to vi key-bindings, rather than emacs. (My solution is to use bash for interactive shells.) Common utilities (such as grep) are implemented differently across different platforms thereby preventing perfect portability. Some useful commands need to be installed on some platforms and are part of the OS core on others. The syntax for conditionals is overly heavy. (if [ ... ]; then ... fi) Although it is Turing Complete, you are eventually going to want to move up to a more expressive language like Perl.

第4个问题的一个解决方案是习惯短路评估:

[ ... ] && ...