On Wed, Jun 4, 2014 at 3:40 PM, Stefan Monnier <monnier@iro.umontreal.ca>
wrote:

> > For instance Edward Bishop's vtags fork?
>
> I know nothing about it.  If we can get its copyright cleared, then it'd
> probably be a good starting point (we'd probably want to try and
> integrate it more with the current tags functionality).
>

My reason for using vtags has never been the additional annotations.  They
just turned out to be an unexpected extra.  The important thing about vtags
is that it assumes a binary searchable external tags file and offers other
UI improvements.  Definitely a source of idea.

/john

;; Added tags (as opposed to TAGS) functionality.
;; The code now has the ability to parse vi-style
;; tags tables generated by Exuberant Ctags.
;; By introduction of vtags-get-tagfile-header and struct tagfileinfo, we
have tried
;; to make the higher-level functions tag-type agnostic and
non-buffer-centric.
;; Many functions that used to assume that the TAGS file is in
;; the current buffer now take a tagfileinfo, or tfi, parameter.
;;
;; Changed the behavior of vtags-find for multiple matches. Previously the
user
;; could iterate through the matches one at a time. Now the user
;; is presented with all the matches at once in a buffer, similar
;; to the way that completions, list-tags, or tags-apropos are handled.
;; Removed next-p in vtags-find-internal, etc. Now vtags-find-internal
searches all tag files.
;;
;; Deprecated the tag ring in favor of placeholders.
;; Placeholders navigation is more natural, allowing forward and back,
;; similar to the way debuggers allow programmers to navigate up and down
;; a call stack, or to the way browsers allow history navigation.
;;
;; Ripped out cached completions, i.e. tags-completion-table.
;; These are not useful since they take forever to compute without a prefix
;; (and people almost never use completion without a prefix).
;;
;; Eliminated tags-file-name. Users should use vtags-table-list instead.
;; There were too many global variables tracking
;; the same or overlapping functionality.
;;
;; Eliminated select-tags-table and all other references to
tags-table-set-list.
;; There may be some merit to allowing the user to select a set of tags
tables
;; from a list of sets, but it seems to me that the previous implementation
;; was too complicated, too rigid, and too poorly documented, and too
implicitly
;; entangled with the rest of the tags functionality to be easily
salvageable.
;; See Design Notes below.
;;
;; Eliminated `tags-table-computed-list'. There is no evidence that
;; this optimization was needed.  Let Emacs and the OS cache file stats
;; if needed.
;;
;; Removed 'button and 'apropos dependency, using vtags-mode instead.
;; We don't need all the features of button and apropos, and removing
;; them makes the code more portable and independent.