switch to calver; add g:vimwiki_version; tidy version hardcoding

Setting a global for g:vimwiki_version doesn't seem too egregious, and
lets us reference it cleanly elsewhere.

Removes version header from vimwiki.txt and hardcoding in tagfile
generation.

There's still one instance of that left in test/tag.vader that we should
clean up eventually.

CONTRIBUTING.md

@@ -10,11 +10,13 @@ Issues can be filed at https://github.com/vimwiki/vimwiki/issues/
 
 # Git branching model
 
-As of v2.6.0, VimWiki has adopted a rolling release model, while (for the
+As of v2022.12.02, VimWiki has adopted a rolling release model, along with
-moment) retaining specific version numbers.  A release should be
+[calendar versioning][calver].  A release should be
 [prepared][#preparing-a-release] for every change or set of changes which merge
 to `dev`.
 
+[calver]: https://calver.org/
+
 There are two permanent branches:
     1. `dev`: This is the default branch, and where changes are released. Tasks
        which are done in one or only a few commits go here directly. Always
@@ -34,11 +36,13 @@ not from the `master` branch.
 
 Version bureaucracy:
 
-1. Pick a new version number according to [semver][semver] rules:
+1. Pick a new version number according to the current date:
-   `git tag vMAJOR.MINOR.PATCH`
+   `YYYY.MM.DD` (if releasing a second version for the
-2. Update the version number at the top of `doc/vimwiki.txt`
+   current date, append a `_MICRO` version such as `_1`, `_2`, etc.
-3. Update the version number at the top of `plugin/vimwiki.vim`
+   - Examples: `2022.12.22`, `2022.12.22_1`
-4. Update the version number in `autoload/vimwiki/tags.vim`
+2. Update the version number at the top of `plugin/vimwiki.vim`
+3. Update the `!_TAG_PROGRAM_VERSION` expected in `test/tag.vader`
+   (this is a bit silly, will have to figure out how to get rid of it)
 
 Update `doc/vimwiki.txt` with the following information:
 
@@ -51,7 +55,9 @@ Update `doc/vimwiki.txt` with the following information:
 
 # Preparing a release
 
-1. Set a tag with the version number in Git.
+This section is primarily for maintainers.
+
+1. Set a tag with the version number in Git: `git tag -a v2022.12.02 -m 'Release v2022.12.02'`
 2. `git push --tags`
 3. In GitHub, go to _Releases_ -> _Draft a new release_ -> choose the tag,
    convert the changelog from the doc to Markdown and post it there. Make

autoload/vimwiki/tags.vim

@@ -292,9 +292,8 @@ function! s:write_tags_metadata(metadata) abort
     endfor
   endfor
   call sort(tags, 's:tags_entry_cmp')
-  " TODO: VimWiki version probably shouldn't be hardcoded here:
   let tag_comments = [
-    \ "!_TAG_PROGRAM_VERSION\t2.6.0",
+    \ "!_TAG_PROGRAM_VERSION\t" . g:vimwiki_version,
     \ "!_TAG_PROGRAM_URL\thttps://github.com/vimwiki/vimwiki",
     \ "!_TAG_PROGRAM_NAME\tVimwiki Tags",
     \ "!_TAG_PROGRAM_AUTHOR\tVimwiki",

doc/vimwiki.txt

@@ -8,9 +8,6 @@
              |     | |   | | ||_|| ||   _   ||   | |    _  ||   |            ~
               |___|  |___| |_|   |_||__| |__||___| |___| |_||___|            ~
 
-
-                               Version: 2.6.0
-
 ==============================================================================
 CONTENTS                                                             *vimwiki*
 
@@ -3995,14 +3992,17 @@ https://github.com/vimwiki/vimwiki/issues/, all others from
 http://code.google.com/p/vimwiki/issues/list. They may be accessible from
 https://github.com/vimwiki-backup/vimwiki/issues.
 
-From version 2.6.0, the VimWiki project has adopted a rolling release policy.
+From version 2022.12.02, what would have been 2.6.0 under the prior versioning
-Once changes are accepted, they will merge directly to dev, which is now the
+scheme, the VimWiki project has adopted a rolling release policy.  Once changes
-main branch.  master is retained as a legacy mirror of the dev branch.
+are accepted, they will merge directly to dev, which is now the main branch.
+master is retained as a legacy mirror of the dev branch.
 
-2.6.0 (2022-11-28)~
+This is somewhat experimental, and will probably be refined over time.
+
+2022.12.02~
 
 New:~
-    * Policy: #1235: Move to semver and rolling release cadence
+    * Policy: #1235: Move to calendar versioning and rolling release cadence
     * Feature: #238: Reuse existing tabs with tab drop
     * Issue #621: Feature request: Highlight code listings in HTML
     * Issue #290: Calendar plugin, do not sign if no wiki

plugin/vimwiki.vim

@@ -11,7 +11,7 @@ endif
 let g:loaded_vimwiki = 1
 
 " Set to version number for release:
-let s:plugin_vers = '2.6.0'
+let g:vimwiki_version = '2022.12.02'
 
 " Get the directory the script is installed in
 let s:plugin_dir = expand('<sfile>:p:h:h')
@@ -209,7 +209,7 @@ endfunction
 " Echo vimwiki version
 " Called by :VimwikiShowVersion
 function! s:get_version() abort
-  echo 'Version: ' . s:plugin_vers
+  echo 'Version: ' . g:vimwiki_version
   let l:plugin_rev    = system('git --git-dir ' . s:plugin_dir . '/.git rev-parse --short HEAD')
   let l:plugin_branch = system('git --git-dir ' . s:plugin_dir . '/.git rev-parse --abbrev-ref HEAD')
   let l:plugin_date   = system('git --git-dir ' . s:plugin_dir . '/.git show -s --format=%ci')

test/tag.vader

@@ -159,7 +159,7 @@ Expect (Correctly formatted tags file):
   !_TAG_PROGRAM_AUTHOR	Vimwiki
   !_TAG_PROGRAM_NAME	Vimwiki Tags
   !_TAG_PROGRAM_URL	https://github.com/vimwiki/vimwiki
-  !_TAG_PROGRAM_VERSION	2.6.0
+  !_TAG_PROGRAM_VERSION	2022.12.02
   second-tag	Test-Tag.md	13;"	vimwiki:Test-Tag\tTest-Tag#second-tag\tTest-Tag#second-tag
   test-tag	Test-Tag.md	5;"	vimwiki:Test-Tag\tTest-Tag#a-header\tA header
   top-tag	Test-Tag.md	1;"	vimwiki:Test-Tag\tTest-Tag\tTest-Tag