PATCH: completing dates and times for git

[Oliver Kiddle <opk@xxxxxxx>]

Git accepts dates/times in a flexible but very specific form. I can
never quite remember what the rules for this are and reading the source
code is rather more helpful than the documentation for understanding.
git rev-parse --since= can be used to verify how things are interpreted.

This adds handling for it to the completion. It will use _dates if
you start with "20" for the year. A description passed to the
function is still used with compadd -x so, e.g. after git gc --prune=
the list will start with the description "date [2 weeks ago]" before
breaking it down into months, weekdays etc. The word "ago" is widely
used in examples in git documentation but absent from the completion
because it is simply ignored and does nothing.

"approxidate" is the term git uses even in the documentation. Some
options take other formats.

Oliver

diff --git a/Completion/Unix/Command/_git b/Completion/Unix/Command/_git
index 1c3a95031..1d4fe20c9 100644
--- a/Completion/Unix/Command/_git
+++ b/Completion/Unix/Command/_git
@@ -996,7 +996,7 @@ _git-gc () {
   _arguments -S -s $endopt \
     '--aggressive[more aggressively optimize]' \
     '--auto[check whether housekeeping is required]' \
-    '(        --no-prune)--prune=-[prune loose objects older than given date]::date [2 weeks ago]:__git_datetimes' \
+    '(        --no-prune)--prune=-[prune loose objects older than given date]::date [2 weeks ago]:_git_approxidates' \
     '(--prune           )--no-prune[do not prune any loose objects]' \
     '(-q --quiet)'{-q,--quiet}'[suppress progress reporting]' \
     '--keep-largest-pack[repack all other packs except the largest pack]' \
@@ -2371,10 +2371,14 @@ _git-worktree() {
           _arguments -S $endopt \
 	    '(-n --dry-run)'{-n,--dry-run}"[don't remove, show only]" \
 	    '(-v --verbose)'{-v,--verbose}'[report pruned objects]' \
-            '--expire=[expire objects older than specified time]:time' && ret=0
+            '--expire=[expire objects older than specified time]: :_git_approxidates' && ret=0
 	;;
         (list)
-	  _arguments -S $endopt '--porcelain[machine-readable output]' && ret=0
+          _arguments -S $endopt \
+            '(-v --verbose --porcelain -z)'{-v,--verbose}'[output additional information about worktrees]' \
+            "--expire=[add 'prunable' annotation to worktrees older than specified time]: :_git_approxidates" \
+            '(-v)--porcelain[machine-readable output]' \
+            '(-v)-z[terminate each line with a NUL rather than a newline]' && ret=0
 	;;
 	(lock)
 	  _arguments -C -S $endopt '--reason=[specify reason for locking]:reason' ': :->worktrees' && ret=0
@@ -3851,7 +3855,7 @@ _git-prune () {
     '(-n --dry-run)'{-n,--dry-run}'[do not remove anything; just report what would be removed]' \
     '(-v --verbose)'{-v,--verbose}'[report all removed objects]' \
     '--progress[show progress]' \
-    '--expire=[only expire loose objects older than specified date]: :__git_datetimes' \
+    '--expire=[only expire loose objects older than specified date]: :_git_approxidates' \
     '--exclude-promisor-objects[limit traversal to objects outside promisor packfiles]' \
     '*:: :__git_heads'
 }
@@ -3899,8 +3903,8 @@ _git-reflog () {
             _arguments -S \
               '(-n --dry-run)'{-n,--dry-run}"[don't actually prune any entries; show what would be pruned]" \
               '--stale-fix[prune any reflog entries that point to "broken commits"]' \
-              '--expire=-[prune entries older than given time]: :__git_datetimes' \
-              '--expire-unreachable=-[prune entries older than given time and unreachable]: :__git_datetimes' \
+              '--expire=-[prune entries older than given time]:age [90 days]:_git_approxidates' \
+              '--expire-unreachable=-[prune entries older than given time and unreachable]:age [30 days]:_git_approxidates' \
               '--all[prune all refs]' \
               '--updateref[update ref with SHA-1 of top reflog entry after expiring or deleting]' \
               '--rewrite[adjust reflog entries to ensure old SHA-1 points to new SHA-1 of previous entry after expiring or deleting]' \
@@ -4046,8 +4050,10 @@ _git-repack () {
   _arguments -s \
     '(-A --unpack-unreachable)-a[pack all objects into a single pack]' \
     '(-a -k --keep-unreachable)-A[pack all objects into a single pack, but unreachable objects become loose]' \
+    '--cruft[pack unreachable cruft objects separately]' \
+    '--cruft-expiration=[expire cruft objects older than specified time]: :_git_approxidates' \
     '-d[remove redundant packs after packing]' \
-    "--unpack-unreachable=[with -A, don't loosen objects older than specified date]:date" \
+    "--unpack-unreachable=[with -A, don't loosen objects older than specified date]: :_git_approxidates" \
     '-f[pass --no-reuse-delta option to git pack-objects]' \
     '-F[pass --no-reuse-object option to git pack-objects]' \
     "-n[don't update server information]" \
@@ -4055,7 +4061,7 @@ _git-repack () {
     '(-l --local)'{-l,--local}'[pass --local option to git pack-objects]' \
     '(-b --write-bitmap-index)'{-b,--write-bitmap-index}'[write a bitmap index]' \
     '(-i --delta-islands)'{-i,--delta-islands}'[pass --delta-islands to git-pack-objects]' \
-    "--unpack-unreachable=[with -A, don't loosen objects older than specified time]:time" \
+    "--unpack-unreachable=[with -A, don't loosen objects older than specified time]: :_git_approxidates" \
     '(-k --keep-unreachable)'{-k,--keep-unreachable}'[with -a, repack unreachable objects]' \
     '--window=[number of objects to consider when doing delta compression]:number of objects' \
     '--window-memory=[scale window size dynamically to not use more than specified amount of memory]: : __git_guard_bytes' \
@@ -4358,8 +4364,8 @@ _git-rev-parse () {
       '--is-inside-work-tree[show whether or not current working directory is inside work tree]' \
       '--is-bare-repository[show whether or not repository is bare]' \
       '(--revs-only --no-revs --flags --no-flags --verify)--short=-[show only shorter unique name]:: :__git_guard_number length' \
-      '(--since --after)'{--since=-,--after=-}'[show --max-age= parameter corresponding given date string]:datestring' \
-      '(--until --before)'{--until=-,--before=-}'[show --min-age= parameter corresponding given date string]:datestring' \
+      '(--since --after)'{--since=-,--after=-}'[show --max-age= parameter corresponding given date string]: :_git_approxidates' \
+      '(--until --before)'{--until=-,--before=-}'[show --min-age= parameter corresponding given date string]: :_git_approxidates' \
       '--resolve-git-dir[check if <path> is a valid repository or gitfile and print location]:git dir:_files -/' \
       '*: :__git_objects' && ret=0
   fi
@@ -4399,7 +4405,7 @@ _git-show-branch () {
       if compset -P '[[:digit:]]##,'; then
         _alternative \
           'counts: :__git_guard_number count' \
-          'dates::__git_datetimes' && ret=0
+          'dates::_git_approxidates' && ret=0
       else
         __git_guard_number limit
       fi
@@ -4961,7 +4967,7 @@ _git-commit-graph() {
       '(--reachable --stdin-packs)--stdin-commits[walk commits starting at commits read from input]'
       '(--append)--size-multiple=:commits [2]'
       '(--append)--max-commits=:commits'
-      '(--append)--expire-time=:date/time:__git_datetimes'
+      '(--append)--expire-time=: :_git_approxidates'
       '--max-new-filters=[specify maximum number of changed-path bloom filters to compute]:'
     )
   elif [[ $words[2] = verify ]]; then
@@ -5130,7 +5136,9 @@ _git-pack-objects () {
     '--include-tag[include unasked-for annotated tags if object they reference is included]' \
     '(--revs --stdin-packs --unpack-unreachable)--keep-unreachable[add objects unreachable from refs in packs named with --unpacked to resulting pack]' \
     '(--revs --stdin-packs)--pack-loose-unreachable[pack unreachable loose objects]' \
-    '(--revs --stdin-packs --keep-unreachable)--unpack-unreachable=-[keep unreachable objects in loose form]::time' \
+    '(--revs --stdin-packs --keep-unreachable)--unpack-unreachable=-[keep unreachable objects in loose form]:: :_git_approxidates' \
+    '--cruft[create a cruft pack]' \
+    '--cruft-expiration=[expire cruft objects older than specified time]: :_git_approxidates' \
     '--sparse[use sparse reachability algorithm]' \
     '--include-tag[include tag objects that refer to objects to be packed]' \
     $thin_opt \
@@ -7626,10 +7634,65 @@ __git_guard_bytes () {
   _numbers -u bytes ${*:-size} k m g
 }
 
-(( $+functions[__git_datetimes] )) ||
-__git_datetimes () {
-  # TODO: Use this in more places.
-  _guard '*' 'time specification'
+(( $+functions[_git_approxidates] )) ||
+_git_approxidates() {
+  local MATCH MBEGIN MEND
+  local match mbegin mend
+  local -i date time num
+  local -a months=( January February March April May June July August September
+      October November December )
+  local -a weekdays=( Sunday Monday Tuesday Wednesday Thursday Friday Saturday )
+  local -a numbers=( zero one two three four five six seven eight nine ten )
+  local -a periods=( second minute hour day week month year )
+  local -a suf=( -S. -r "._,+\\ \t\n\-" )
+
+  local -a pexpl
+  zparseopts -D -E X+:=pexpl
+
+  local -a query=(
+    \( /$'*\0[ \t\n]#'/ \)
+    \( '/[]/' ':dates:date:compadd "${pexpl[@]:/-X/-x}"'
+    \| '/(@|[0-9](#c9))/' ':specials:special:compadd -S "" @' '/[]/' ': _message -e epochtimes "seconds since Unix epoch"'
+    \| '/(#i)(now|never)/' '%?%' ':specials:special:(now never)' '/[]/'
+    \| \)
+    \(
+      \( '/(#i)(one|last)/' '%[ ._,+]%' -'num=1'
+      \| '/[0-9](#c2,4)(-|/|.|)[0-9](#c1,2)(-|/|.|)[0-9](#c1,4)(|T)/' -'date=3'
+      \| '/[0-9](#c2)(:|)[0-9](#c2)(:|)[0-9](#c2)(.<->|)/' -'time=1'
+      \| '/20/' -'((!date))' '/[]/' ':dates:date:_dates -f "%y-%m-%d"'
+      \| '/1/' -'num=1'
+      \| '/<->/' -'num=2'
+      \| "/(#i)(${(j.|.)numbers})/" '%[ ._,+]%' -'num=2'
+      \| "/(#i)(${(j.|.)${(@)months//(#b)(???)(*)/$match[1]${match[2]//(#m)?/(|$MATCH}${match[2]//?/)}}})/"
+         '%[ ._,+]%' -'(( num = 0, date |= 2 ))'
+      \| "/(#i)(${(j.|.)${(@)weekdays//(#b)(???)(*)/$match[1]${match[2]//(#m)?/(|$MATCH}${match[2]//?/)}}})(|s)/"
+         '%[ ._,+]%' -'(( num = 0, date |= 1 ))'
+      \| '/(#i)yesterday/' '%[ ._,+]%' -'date=3'
+      \| "/(#i)(${(j.|.)${(@)periods%s}})(|s)/" '%[ ._,+]%' -'num=0'
+      \| '/(#i)(noon|midnight|tea|[ap]m)/' '%[ ._,+]%' -'time=1'
+      \|
+        \( // -'(( !(date&2) ))' // ':months:month:compadd -o nosort $suf -a months' \| \)
+        \( // -'(( num <= 1 && !(date&1) ))' // ':weekdays:weekday:compadd $suf -o nosort -a weekdays' \| \)
+        \( // -'(( num > 1 ))'
+          \( // -'(( date < 3 ))' // ':periods:period:compadd $suf -o nosort ${^periods[4,-1]}s' \| \)
+          \( // -'(( !(date&1) ))' // ':weekdays:weekday:compadd $suf -o nosort ${^weekdays}s' \| \)
+          \( // -'(( !time ))' // ':periods:period:compadd $suf -o nosort ${^periods[1,3]}s' \| \)
+        \| // -'(( num == 1 ))'
+          \( // -'(( date < 3 ))' // ':periods:period:compadd $suf -o nosort -a "periods[4,-1]"' \| \)
+          \( // -'(( !time ))' // ':periods:period:compadd $suf -o nosort -a "periods[1,3]"' \| \)
+        \| // -'(( num == 0 ))'
+          \( // -'(( !time ))' // ':specials:special:compadd $suf noon midnight tea AM PM' \| \)
+          \( // -'(( !date ))' // ':specials:special:compadd $suf yesterday' \| \)
+          // ':specials:special:compadd $suf last' # "last" is equivalent to "one"
+          // ':numbers:number:compadd $suf -n -o nosort -a numbers'
+        \)
+        '/[]/'
+      \) '/([ ._,+]|)/'
+    \) \#
+  )
+
+  _regex_arguments _git_dates "$query[@]"
+  _git_dates
 }
 
 (( $+functions[__git_stages] )) ||
@@ -7923,8 +7986,8 @@ __git_setup_revision_options () {
     '--count[display how many commits would have been listed]'
     '(-n --max-count)'{-n+,--max-count=}'[maximum number of commits to display]: :__git_guard_number'
     '--skip=[skip given number of commits before output]: :__git_guard_number'
-    '(--max-age --since --after)'{--since=,--after=}'[show commits more recent than given date]:date'
-    '(--min-age --until --before)'{--until=,--before=}'[show commits older than given date]: :__git_guard_number timestamp'
+    '(--max-age --since --after)'{--since=,--after=}'[show commits more recent than given date]: :_git_approxidates'
+    '(--min-age --until --before)'{--until=,--before=}'[show commits older than given date]: :_git_approxidates'
     '(          --since --after)--max-age=-[maximum age of commits to output]: :__git_guard_number timestamp'
     '(          --until --before)--min-age[minimum age of commits to output]: :__git_guard_number timestamp'
     '*--author=[limit commits to those by given author]:author'