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

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:

[ ... ] && ...

其他回答

Python。

虽然前面提到了python处理作用域的奇怪方式,但我觉得最糟糕的结果是:

import random

def myFunction():

    if random.choice(True, False):
        myString = "blah blah blah"

    print myString

也就是说,if块内部的作用域与函数的其余部分相同,这意味着变量声明可以出现在条件分支内部,并且可以在条件分支外部访问。大多数语言要么阻止你这样做,要么至少为你提供某种严格的模式。

此函数有时会成功,但有时会抛出异常。虽然这是一个人为的例子,但这可能会导致一些微妙的问题。

EL -表达式语言,${…}和#{…JSF 2.0 Facelets用于从底层Java代码中提取数据。

All the fun things, like method calls with parameters and annotation based naming is only present in the EL in Java EE 6 which is only available in Glassfish v3. It is a royal pain to 1) get the right jars for an earlier Servlet 2.5 container, and 2) getting them to work without interfering with any previous implementation available in the container. Having only an earlier version of JSF like 1.2, takes away the method calls and leave you to work with f:setPropertyActionListener - http://weblogs.java.net/blog/2009/07/22/say-sayonara-spal - which, trust me on this, is not very nice. The EL parser has no idea of where the snippet it is to parse and interpret came from, so you tend to give everything an id so you at least can identify which tag made it grumpy. Eclipse gives a warning at every EL method call as it is JSF 1.2. only too.

Haskell:

惰性计算导致空间泄漏。 数字层次结构不是根据数学抽象构造的。 严格的单元IO会使调试更加困难。 大型实现处理I/O的方式似乎与标准不太兼容。(特别是,输出字符只输出低8位——然后构建代码,使用这个假设来执行二进制I/O。我吐!) ($)运算符的结合性可以被改变以使某些表达式更漂亮。

大多数问题都不会上升到讨厌的程度,有些人试图解决或为每一个问题构建可靠的变通办法。

编辑:关于第5点有些困惑。特别是有些人似乎认为我指的是论证的顺序,但我不是。我不解释我的意思,我只想让人们去下面的链接http://hackage.haskell.org/trac/haskell-prime/wiki/ChangeDollarAssociativity,它很好地表达了我的意思。

Objective Caml

缺少名称空间。 啰嗦类和对象注释。 复杂的构建系统。 不方便制作中缀。

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) { ... }