Refined exuberant-ctags extension for Scala

[liancheng]

The original ctags extension performs poorly when locating various tags, for example, here are some bad cases:

• evaluator: the val substring in evaluator is parsed as the keyword val and a value tag named uator is generated.
• private[this] class T: (case) classes/(case) objects/values/variables with access qualifiers are not recognized.
• notaclass T: generates a wrong class tag T

The new extension refined all --regex-scala options to locate tags much more accurately, and added two new tag types, namely case-objects and packages.

[liancheng]

Here are some test cases:

package emacs.contrib

private[this] abstract class PrivateAbstractClassWithAccessQualifier
abstract private[this] class AbstractPrivateClassWithAccessQualifier

private abstract class PrivateAbstractClass
abstract private class AbstractPrivateClass

sealed protected[contrib] class SealedProtectedClassWithAccessQualifier
protected[contrib] sealed class ProtectedSealedClassWithAccessQualifier

sealed protected class SealedProtectedClassWithAccessQualifier
protected sealed class ProtectedSealedClassWithAccessQualifier

implicit protected[contrib] object ImplicitProtectedObjectWithAccessQualifier
protected[contrib] implicit object ProtectedImplicitObjectWithAccessQualifier

protected case object ProtectedCaseObject
protected case class ProtectedCaseClass

protected[this] val intValWithType: Int = 1
protected[this] val intVal = 1

protected[this] var intVarWithType: Int = 1
protected[this] var intVar = 1

private[this] def unary_+(n: Int): Int

trait Trait
type Type

[adriaanm]

Thanks! I'm really sorry we haven't gotten back to you sooner.
We're looking for someone to maintain this github repository, as we're kind of overloaded maintaining scala/scala itself. Please sign the Scala CLA online, confirm here, and I'll merge this ASAP.

[liancheng]

I've signed the Scala CLA. Thanks for your effort!

[adriaanm]

Thank you!

[simonrad]

Hi @liancheng,
For some reason these regexes are not working for me. They generate no scala tags, even for the test cases you provided. It does work with the previous version of the regexes. I'm using Exuberant Ctags 5.8 installed via homebrew on Mac OS X.

[liancheng]

Hi @simonrad, would you mind to elaborate how you configured your Exuberant Ctags? And here is a minimized version of my configuration, which works fine under both CentOS 6.4 and Ubuntu 12.04:

1. Copy dot-ctags to $HOME/.ctags
2. Install the taglist-plus Vim plugin
3. Add these lines to .vimrc:

" Taglist Scala support
let tlist_scala_settings = 'scala;' .
                         \ 'p:packages;' .
                         \ 'a:abstract classes;' .
                         \ 'c:classes;' .
                         \ 'm:case classes;' .
                         \ 'o:objects;' .
                         \ 'M:case objects;' .
                         \ 't:traits;' .
                         \ 'T:types;' .
                         \ 'f:functions;' .
                         \ 'V:values;' .
                         \ 'v:variables'

With this configuration I can generate proper tags file and view tags in Vim. To generate tags file, only step 1 is needed. Hope to be helpful.

[mhamrah]

I can't use the newer ctags with ctags 5.8 and vim either. Is taglist-plus required? My ctags file looks exactly like the ctags file in this repository. The original file works when recursively tagging via

ctags -R . --exclude=target --exclude=.git

when using the newer version of the ctags configuration, no .scala files indexed in the tags file.

[liancheng]

Hey @mhamrah and @simonrad, sorry for not being helpful for such a long time. I wasn't able to reproduce this bug until I got a Mac and hit right the same issue. After some investigation it turned out that ctags under Mac OS X somehow doesn't recognize some POSIX extended regex syntax like \<, \> and \s. And it works for me after replacing them with [[:space:]], [[:<:]] and [[:>:]]. Will submit a PR for this.

[liancheng]

@mhamrah @simonrad Here is the PR: #137

[mhamrah]

Nice!

On Fri, Jul 11, 2014 at 6:47 PM, Cheng Lian [email protected]
wrote:

@mhamrah https://github.com/mhamrah @simonrad
https://github.com/simonrad Here is the PR: #137
#137

—
Reply to this email directly or view it on GitHub
#95 (comment).

[simonrad]

Awesome! Thank you.