Is there a way to use perl-style regular expressions in Emacs? I use regexp-builder and query-replace-regexp pretty often but the Emacs-style regexes throw me off sometimes.
After a bit more searching I found a few similar questions:
Is it possible to change emacs' regexp syntax?
Elisp mechanism for converting PCRE regexps to emacs regexps
It looks like the solutions is to write an elisp function to convert PCRE's to Emacs-style regexes. This code on GitHub looks like a pretty good option.
Related
I am developing my own Domain Specific Language (DSL) and the filename extension is .xyz.
Emacs doesn't know how to highlight syntax in .xyz files so I uausally turn on typescript-mode or json-mode. But the available syntax highlight mode is not good enough for me, so I am considering writing my own syntax highligher for Emacs editor. Any tips on this task? Any toolkit recommendation?
Alternatively, I would be happy with any available mode that highlights common keywords such as class, string, list, variables before =sign and after # sign, braces {}, brackets [], question mark ? and exclamation mark !. Any existing languages have similar syntax?
I am not color-blind and not picky on colors. Any syntax highligher that highlights above syntax can solve my problem.
If you are satisfied with simple syntax highlighting for keywords and comments only, there is a helper for this called define-generic-mode, which is documented in the elisp manual.
Some examples of using it can be found in generic-x.el distributed with Emacs.
But highlighting of variable names is not covered by this. For that, you need to be able to parse the DSL using semantic/bovine, as whether a particular string is interpreted as a variable name depends on context, and not just simple regexp matching.
According to this page you can use perl compatible regular expression with
:perldo s/pattern/insert/g.
This works fine.
But, how can I get interactive search and replace with PCRE syntax in vim?
Since this does not work with perldo I search for a different solution.
Till the current release version of vim, there is no way to do :s/[perlRegex]/bar/c
So you are asking for a feature that doesn't exist.
You can do matching with verymagic, however it is not Perl Regex compatible flag. It is still using the vimregex engine, just changed the way of escaping regex patterns.
For example, in perl, you can do lookahead/behind (?<=foo)..., (?=foo), (?!foo).., you can use the handy \K : som.*ing\Kwhatever etc, you cannot use those syntax in vim directly, no matter which 'magic' level you have set. Vim has the same feature, but different syntax:
\#=
\#!
\#<=
and also the \zs \ze are very handy, even more powerful than perl's \K.
Vim is an Editor, with vim regex, you can not only do text matching, but also match base on visual selection, cursor position and so on.
If you really need to do complex pattern matching and really need do them in vim, learn vim regex! It is not difficult for you if you "know pcre very well"
Probably the closest you can get is:
:s/\vfoo/bar/gc
I suggest to try eregex plugin. It maps perl compatible regular expressions to VIM regex syntax.
In your example, s/pattern/insert/g is a perl command, not a Vim command using a perl-compatible regular expression syntax.
If perl doesn't have an equivalent of Vim's /c flag you will need to find an alternate method like… writing an actual perl script.
I'm trying to improve Emacs highlighting of Common Lisp and I'm stuck at regexp approach to highlighting used by font-lock. Regexps aren't enough as I want to be able to recognize structure of such forms as defun - highlighting of functions' argument list should be different from the bodys' highlighting, not just global search-and-highlight.
So, are there any alternatives to font-lock in Emacs itself or somewhere in the Internet? And if so, does they operate on symbolic expressions?
Emacs' font-lock matching is not restricted to regular-expression; you can use any function as matcher provided it satisfies certain protocol. Take a look at the variable font-lock-keywords for more details.
C-h vfont-lock-keywords
I think, that something like could be done on base of Semantic (part of CEDET package) - you can get syntactic information from parsed buffer and apply different color for different types of objects. Although I don't know any existing implementation right now
Recently I've started using emacs and after overcoming a number of hurdles in making cperl-mode operate in a way that is agreeable I've become stumped by this problem. Currently I have all scalars in regular use being highlighted except for where they are interpolated. Is such syntax highlighting possible under this mode? Currently I'm using emacs 23.1 and jrockway's cperl-mode 5.23
Thanks
It won't highlight interpolated variables in strings, but it will do it in regular expressions. I'll bet that could be adapted by somebody who knows elisp.
When I run Emacs command ispell-buffer on an Emacs buffer which is in the LaTeX mode, ispell checks spelling also inside math expressions.
I'd very much like to disable this. Is there an easy way to do it?
I've read about detex but detex does not seem to be integrated into Emacs.
It shouldn't do this, if you are using latexisms (eg. \[ ... \], equation environments, &c) to invoke math mode. Check the contents of ispell-tex-skip-alists; cf. section 6 of the ispell FAQ for what kind of thing should be there.
You can use $..$, $$..$$ to mark out maths using ispell-tex-skip-alists, but beware getting them out of kilter...
Postscript
Check also the value of the ispell-parser variable: this should be 'tex, otherwise ispell will not look for $...$ and $$...$$ regions.
Yes, you can: install aspell instead of ispell, and use flyspell with it.
This doesn't answer your question directly, but I have found Flyspell, an on-the-fly spell checker, incredibly useful when editing LaTeX documents. It still spellchecks inside equations, but it is much easier to ignore a few extra red underlines than ispell's interactive commands.
You may know this, but you can press A during spell checking to add a word to the buffer-local dictionary (that's capital A, lowercase a adds it to the global dictionary). It's not ideal, but this is how I usually suppress spell-checking of technical terms and variable names, etc., in my LaTeX documents.
This AUCTeX mailing list thread : "spell checker (ispell-buffer) complains about products in math modes" has some workarounds and the answer demonstrates how to use ispell-tex-skip-alists.
Another approach is to use ispell-skip-region-alist. The following example is to exclude org-mode src blocks:
(add-to-list 'ispell-skip-region-alist '("#\\+begin_src". "#\\+end_src"))