Emacs中perl的语法高亮被打破了，有没有修复？ [英] Syntax highlight for perl in Emacs is broken, is there a fix?

问题描述

我是一个Perl程序员和一个新的emacs用户。我在Windows下，使用cperl-mode进行编辑perl。 Emacs版本是24.2.1。以下是一些示例代码的截图：

http ：//breqwas.net/dropbox/perlsyn_emacs.png

1. 明显的错误：它突出显示数组，散列和非引号文字值（ a =>b）样式列表里面的评论


2. 还有一个bug：由于非默认值，它将正则表达式中的第一个单词作为数组高估引用符号


3. 不是一个错误，但看起来很奇怪：它突出显示数组和任何时候使用它们的哈希（即使在注释中），但标量仅在声明时被突出显示


4. 不是一个错误，但看起来很奇怪：与功能相同的故事：声明时突出显示，而不是调用时


5. 不是一个错误，但看起来很奇怪：为什么打印，说和系统有不同的颜色？

我可以继续下去，但我希望能够很好地解释破

然后我学到了魔法铜C-x =键组合，其中显示了光标下的文本的文本属性，希望能够使自己更好的着色方案。在这一点上，它开始变得没有意义。

print具有 cperl-nonoverstrable-face 。 死有 font-lock-keyword-face 。同时，两者都是功能，并且可以（并且经常被）超越。 系统具有 font-lock-type-face 。为什么？函数声明具有 font-lock-function-name-face - 没关系，use的参数也是如此。为什么？函数调用和标量根本没有face属性，不能突出显示。为什么？等等再次，我可以继续前进。

有没有办法解决所有这些？有没有一些配置，我可以将词汇单位重新映射到某些其他字体，或者其他一些方法使语法突出显示更不疯狂？

为了避免perl is不可否认的谈话，这里是我正在迁移的编辑器的截图，使用相同的代码： http： //breqwas.net/dropbox/perlsyn_pn.png 。看起来更合理

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更新：现在（在这里提出这个问题后3周），我没有找到治愈。所有使用emacs的perl程序员，我知道只是忽略这些问题。没有更好的perl荧光笔emacs似乎存在。阅读cperl-mode docs提供了一些解释（现在各种元素的面部选择似乎不那么疯狂），但不提供任何答案。我写了一封电子邮件给cperl-mode维护者，这些问题和一些挖掘我做了，但没有回复。

是的，你的权利：看起来像emacs社区在25年的时间里，Perl无法使一个很好的perl语法高效。这是一个难过的故事。

解决方案

您可能想尝试 perl-mode 而不是 cperl-mode 。如果您发现缺少的功能，我们可以将它们从 cperl-mode 中移植，而不会有太多麻烦。 perl-mode 的突出显示不如 cperl-mode ，但它确实解决了一些问题指出。

至于声明时突出显示，而不是被调用，这是因为Emacs通常以这种方式突出显示。我发现突出变量和功能使用没有好处。我在 perl-mode 中强调变量使用的重点，主要是因为它在之前，我不想处理不满的用户。此外，在Perl的情况下，与 perl-mode 相比，可以更容易地突出显示变量声明和使用方法，而 cperl-mode 必须做额外的工作来区分这两种情况。

I'm a perl programmer and a new emacs user. I'm under Windows, using cperl-mode for editing perl. Emacs version is 24.2.1. Here's a screenshot with some sample code:

http://breqwas.net/dropbox/perlsyn_emacs.png

1. Obvious bug: it highlights arrays, hashes and non-quoted literal values in ( a => "b" ) style lists inside comments
2. One more bug: it highligts the first word in a regular expression as an array because of non-default quote symbol
3. Not a bug, but looks weird: it highlights arrays and hashes any time when they are used (even in comments, huh), but scalars are highlighted only when declared
4. Not a bug, but looks weird: same story with functions: highlighted when declared, not when called
5. Not a bug, but looks weird: why do "print", "say" and "system" have different colors?

I could keep going, but I hope that explains the word "broken" pretty well.

Then I learned the magic C-u C-x = key combination, which shows, among other stuff, the text properties for the text under the cursor, hoping to make a better coloring scheme of my own. At this point it started making even less sense.

"print" has cperl-nonoverridable-face. "die" has font-lock-keyword-face. Meanwhile, both are functions and can be (and often are) overrided. "system" has font-lock-type-face. Why? Function declarations have font-lock-function-name-face - that's OK, but so do the arguments of "use". Why? Function calls and scalars don't have face property at all and can't be highlighted. Why? Etc, Etc. Again, I could keep going.

Is there a way to fix all that? Is there some config where I can remap lexical units to some other font-faces, or some other way to make the syntax highlight less crazy?

To avoid the "perl is unparsible" talk, here's a screenshot of the editor I'm migrating from, with the very same code: http://breqwas.net/dropbox/perlsyn_pn.png. Looks much more reasonable.

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Upd: By now (3 weeks after asking this question here) I did not find a cure. All perl programmers who use emacs I know just ignore these problems. No better perl highlighters for emacs seem to exist. Reading cperl-mode docs provides some explanations (the choice of faces for various elements seems less crazy now), but does not provide any answers. I wrote an email to cperl-mode maintainer with these questions and some more digging I did, but got no reply.

Yep, you got that right: seems like emacs community was not able to make a good perl syntax highligting in 25 years that perl is around. That's a sad story.

解决方案

You might want to try perl-mode instead of cperl-mode. If you find missing features in it we might be able to port them from cperl-mode without too much trouble. perl-mode's highlighting is less gaudy than cperl-mode's but it does fix some of the problems you point out.

As for "highlighted when declared, not when called" this is because Emacs usually highlights in this way. I find there is zero benefit to highlighting variable and function uses. I kept the highlighting of variable uses in perl-mode mostly because it was there before and I didn't want to deal with disgruntled users. Also, in the case of Perl, it's probably easier to highlight variable declarations and uses identically as does perl-mode whereas cperl-mode has to do extra work to distinguish those two cases.

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