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。
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) { ... }
哇,我很惊讶SQL还没有出现在这里。我猜这意味着没有人喜欢它:)
跨实现的语法不一致
细微的代码差异可能会因为看似模糊的原因而产生巨大的性能影响
对文本操作的支持很差
入门成本低,但掌握这门语言的学习曲线陡峭
最大限度地标准化社区的最佳实践,这包括语法风格。
...还有一些额外的讨厌它的理由,不需要额外收费
the WHERE clause goes last, making it easy to prematurely execute an UPDATE or DELETE, destroying the whole table. Instead, the WHERE should go somewhere up front.
It's difficult to implement relational division.
I can set a value to NULL, but I can't test it for equality with NULL. I can check IS NULL, but that just complicates code -- needlessly so, in my opinion.
Why do we need to completely respecify the formula for a GROUPed column, rather than setting an alias on the column and then GROUP BY the alias (or column index as with SORT)?
C#
1)缺乏为值类型编写泛型的实际能力。例如,任何白痴(好吧,大多数白痴)都可以编写一个例程,用c++计算int, float, double等列表的标准偏差,它写起来很简单,易于阅读,并作为快速的非泛型代码执行。我认为,如果你能用c#写一些东西,接近于达到这三个中的任何一个,而在其他两个上又不荒谬,你就是一个真正伟大的程序员。
2)协方差和反方差,尽管这被添加到4。
3)非常糟糕的LINQ文档(好吧,并不是语言的一部分)。
4)尝试使用foreach/迭代器,当我每次都想做同样的事情,除了上次略有不同(如连接一串字符串与逗号之间的单词和最后两个)。如果我用一个IEnumerable来写它,它很难写和读,而用一个for (int I =0 I <…)它并没有好到哪里去,而且效率更低。
5)我知道我会收到抱怨,但是缺少受控的例外。这并不需要像在java中那样实现(框架开发人员确实提出了一些很好的观点,为什么他们没有这样做),但我很乐意看到编译器警告不喜欢受控异常的用户可以关闭。
我偶尔会用我喜欢的PHP,而Python会用得太多。
No namespace; everything is in a
kind of very big namespace which is
hell in bigger environments
Lack of standards when it comes to
functions: array functions take a
needle as a first argument, haystack
as second (see array_search).
String functions often take the
haystack first, needle second (see
strpos). Other functions just
use different naming schemes:
bin2hex, strtolower,
cal_to_jd
Some functions have weird return
values, out of what is normal: This
forces you to have a third variable
declared out of nowhere while PHP
could efficiently interpret an empty
array as false with its type
juggling. There are near no other
functions doing the same.
$var = preg_match_all('/regexp/', $str, $ret);
echo $var; //outputs the number of matches
print_r($ret); //outputs the matches as an array
The language (until PHP6) does its
best to respect a near-retarded
backward compatibility, making it
carry bad practices and functions
around when not needed (see
mysql_escape_string vs.
mysql_real_escape_string).
The language evolved from a
templating language to a
full-backend one. This means anybody
can output anything when they want,
and it gets abused. You end up with
template engines for a templating
language...
It sucks at importing files. You
have 4 different ways to do it
(include, include_once, require,
require_once), they are all slow,
very slow. In fact the whole
language is slow. At least, pretty
slower than python (even with a
framework) and RoR from what I
gather.
不过,我仍然喜欢PHP。这是网页开发的电锯:你想要一个小型到中型网站的速度非常快,并确保任何人都可以托管它(尽管配置可能不同)?PHP就在那里,它无处不在,只需要5分钟就可以安装一个完整的LAMP或WAMP堆栈。好吧,我现在要回去用Python工作了……