[PATCH 2/3] Make dynamic dir completion easier to implement

[Marlon Richert <marlon.richert@xxxxxxxxx>]

From: Marlon Richert <marlon.richert@xxxxxxxxx>

In the pre-patch example, the recommended way of implementing this was
as follows:
  _wanted dynamic-dirs expl 'dynamic directory' compadd -S\] ...

However, this is problematic for the following reasons:
- The proper place for handling _wanted or other tag logic is in the
  completion function _dynamic_directory_name, not in each dynamic dir
  name function separately.
- The naming styles of the tag and group are not consistent with those
  used for non-dynamic named directories, namely 'named-directories' and
  'named directory', respectively.
- The example always inserted a `]` suffix, even if the suffix was
  already present on the command line, leading to a double `]]` on the
  command line.
- Code addressing the points the above needed to be duplicated in each
  dynamic dir name function.

This patch fixes these problems by
- moving the completion logic from the example into
  _dynamic_directory_name, so that users don't have to duplicated this
  scaffolding for each dynamic dir name function, and
- adds logic to _dynamic_directory_name for inserting the `]` suffix
  only when needed.
---
 .../Zsh/Context/_dynamic_directory_name       | 30 +++++++++----
 Doc/Zsh/expn.yo                               | 44 +++++++------------
 Test/Y01completion.ztst                       | 11 +++++
 3 files changed, 50 insertions(+), 35 deletions(-)

diff --git a/Completion/Zsh/Context/_dynamic_directory_name b/Completion/Zsh/Context/_dynamic_directory_name
index f449c3b12..e173dcb7f 100644
--- a/Completion/Zsh/Context/_dynamic_directory_name
+++ b/Completion/Zsh/Context/_dynamic_directory_name
@@ -1,15 +1,29 @@
 #autoload
+local -a dirfuncs=(
+   ${(k)functions[zsh_directory_name]}
+   $zsh_directory_name_functions
+)
+local descr='dynamically named directory'

-local func
-integer ret=1
+if (( $#dirfuncs )); then
+  local -a expl=()
+  local -i ret=1
+  local func=
+  local tag=dynamically-named-directories
+  [[ -z $ISUFFIX ]] &&
+      local suf=-S]

-if [[ -n $functions[zsh_directory_name] || \
-  ${+zsh_directory_name_functions} -ne 0 ]] ; then
-  [[ -n $functions[zsh_directory_name] ]] && zsh_directory_name c && ret=0
-  for func in $zsh_directory_name_functions; do
-    $func c && ret=0
+  _tags "$tag"
+  while _tags; do
+    while _next_label "$tag" expl "$descr"; do
+      expl+=( $suf )
+      for func in $dirfuncs; do
+        $func c && ret=0
+      done
+    done
+    (( ret )) || break
   done
   return ret
 else
-  _message 'dynamic directory name: implemented as zsh_directory_name c'
+  _message "${descr}: implement as zsh_directory_name c"
 fi
diff --git a/Doc/Zsh/expn.yo b/Doc/Zsh/expn.yo
index 19f5909ea..6f86d0c54 100644
--- a/Doc/Zsh/expn.yo
+++ b/Doc/Zsh/expn.yo
@@ -2066,34 +2066,24 @@ tt(/home/pws/perforce).  In this simple case a static name for the
 directory would be just as effective.

 example(zsh_directory_name+LPAR()RPAR() {
-  emulate -L zsh
-  setopt extendedglob
+  emulate -L zsh -o extendedglob
   local -a match mbegin mend
-  if [[ $1 = d ]]; then
-    # turn the directory into a name
-    if [[ $2 = (#b)(/home/pws/perforce/)([^/]##)* ]]; then
-      typeset -ga reply
-      reply=(p:$match[2] $(( ${#match[1]} + ${#match[2]} )) )
-    else
-      return 1
-    fi
-  elif [[ $1 = n ]]; then
-    # turn the name into a directory
-    [[ $2 != (#b)p:(?*) ]] && return 1
-    typeset -ga reply
-    reply=(/home/pws/perforce/$match[1])
-  elif [[ $1 = c ]]; then
-    # complete names
-    local expl
-    local -a dirs
-    dirs=(/home/pws/perforce/*(/:t))
-    dirs=(p:${^dirs})
-    _wanted dynamic-dirs expl 'dynamic directory' compadd -S\] -a dirs
-    return
-  else
-    return 1
-  fi
-  return 0
+  local base=/home/pws/perforce
+  case $1 in
+  ( d )  # Turn the directory into a name.
+    [[ $2 == (#b)($base/)([^/]##)* ]] &&
+        reply=( p:$match[2] $(( $#match[1] + $#match[2] )) )
+  ;;
+  ( n )  # Turn the name into a directory.
+    [[ $2 == (#b)p:(?*) ]] &&
+        reply=( $base/$match[1] )
+  ;;
+  ( c )  # Complete names.
+    local -a dirs=( $base/*(/:t) )
+    # Completion system populates $expl with flags for compadd.
+    compadd "$expl[@]" p:$^dirs
+  ;;
+  esac
 })

 texinode(Static named directories)(`=' expansion)(Dynamic named directories)(Filename Expansion)
diff --git a/Test/Y01completion.ztst b/Test/Y01completion.ztst
index 51e246307..2524c43bd 100644
--- a/Test/Y01completion.ztst
+++ b/Test/Y01completion.ztst
@@ -93,6 +93,17 @@
 >line: {: ~user2}{}
 >line: {: ~user1}{}

+  comptesteval 'zsh_directory_name() { compadd "$expl[@]" -- name1 name2 }'
+  comptest $': ~[\t\t\t\t'
+0:dynamic directory names after ~[
+>line: {: ~[name}{}
+>line: {: ~[name}{}
+>DESCRIPTION:{dynamically named directory}
+>NO:{name1}
+>NO:{name2}
+>line: {: ~[name1]}{}
+>line: {: ~[name2]}{}
+
   comptest $'echo ;:\C-b\C-b\t'
 0:directories and files before separator
 >line: {echo }{;:}
--
2.39.2 (Apple Git-143)