From dacacb00aef58048b64f4705923bdb49bc6a8364 Mon Sep 17 00:00:00 2001
From: Simon Ruderich <simon@ruderich.org>
Date: Sun, 8 Feb 2009 16:49:57 +0100
Subject: [PATCH] Simulate hooks using _functions arrays for older versions.

This allows the usage of add-zsh-hook also for older version.

add-zsh-hook is provided in functions/compatibility and was taken from Zsh
4.3.9.
---
 zsh/functions/compatibility/add-zsh-hook | 76 ++++++++++++++++++++++++
 zsh/rc                                   | 19 ++++++
 2 files changed, 95 insertions(+)
 create mode 100644 zsh/functions/compatibility/add-zsh-hook

diff --git a/zsh/functions/compatibility/add-zsh-hook b/zsh/functions/compatibility/add-zsh-hook
new file mode 100644
index 0000000..aedc1e7
--- /dev/null
+++ b/zsh/functions/compatibility/add-zsh-hook
@@ -0,0 +1,76 @@
+# Add to HOOK the given FUNCTION.
+# HOOK is one of chpwd, precmd, preexec, periodic, zshaddhistory,
+# zshexit (the _functions subscript is not required).
+#
+# With -d, remove the function from the hook instead; delete the hook
+# variable if it is empty.
+#
+# -D behaves like -d, but pattern characters are active in the
+# function name, so any matching function will be deleted from the hook.
+#
+# Without -d, the FUNCTION is marked for autoload; -U is passed down to
+# autoload if that is given, as are -z and -k.  (This is harmless if the
+# function is actually defined inline.)
+
+emulate -L zsh
+
+local -a hooktypes
+hooktypes=(chpwd precmd preexec periodic zshaddhistory zshexit)
+
+local opt
+local -a autoopts
+integer del
+
+while getopts "dDUzk" opt; do
+  case $opt in
+    (d)
+    del=1
+    ;;
+
+    (D)
+    del=2
+    ;;
+
+    ([Uzk])
+    autoopts+=(-$opt)
+    ;;
+
+    (*)
+    return 1
+    ;;
+  esac
+done
+shift $(( OPTIND - 1 ))
+
+if (( $# != 2 || ${hooktypes[(I)$1]} == 0 )); then
+  print "Usage: $0 hook function\nValid hooks are:\n  $hooktypes"
+  return 1
+fi
+
+local hook="${1}_functions"
+local fn="$2"
+
+if (( del )); then
+  # delete, if hook is set
+  if (( ${(P)+hook} )); then
+    if (( del == 2 )); then
+      set -A $hook ${(P)hook:#${~fn}}
+    else
+      set -A $hook ${(P)hook:#$fn}
+    fi
+    # unset if no remaining entries --- this can give better
+    # performance in some cases
+    if (( ! ${(P)#hook} )); then
+      unset $hook
+    fi
+  fi
+else
+  if (( ${(P)+hook} )); then
+    if (( ${${(P)hook}[(I)$fn]} == 0 )); then
+      set -A $hook ${(P)hook} $fn
+    fi
+  else
+    set -A $hook $fn
+  fi
+  autoload $autoopts -- $fn
+fi
diff --git a/zsh/rc b/zsh/rc
index 6348432..0d702b0 100644
--- a/zsh/rc
+++ b/zsh/rc
@@ -42,6 +42,25 @@ fpath=(~/.zsh/functions $fpath)
 # to caphuso from the Zsh example files for this idea.
 autoload ${fpath[1]}/^_*(^/:t)
 
+# Simulate hooks using _functions arrays for Zsh versions older then 4.3.4. At
+# the moment only precmd() and preexec() are simulated.
+if [[ $ZSH_VERSION != (4.3.<4->|4.<4->*|<5->*) ]]; then
+    # Provide add-zsh-hook which was added in 4.3.4.
+    fpath=($fpath ~/.zsh/functions/compatibility)
+
+    # Run all functions defined in the ${precmd,preexec}_functions arrays.
+    function precmd() {
+        for function in $precmd_functions; do
+            $function $@
+        done
+    }
+    function preexec() {
+        for function in $preexec_functions; do
+            $function $@
+        done
+    }
+fi
+
 # Autoload add-zsh-hook to add/remove zsh hook functions easily.
 autoload -Uz add-zsh-hook
 
-- 
2.45.2