PATCH: 3.1.5-pws-17: Faster "compinit"

PATCH: 3.1.5-pws-17: Faster "compinit"

[Bart Schaefer]

Not as fast as loading the dumpfile, obviously, but quite a bit faster than
without the patch.  There are probably other things that could be done, but
this does an obvious one:  There are a couple of "if" cascades inside loops
that can be directly rewritten as "case" statements, thereby expanding the
variable only once.  It might even be faster still, in the second case, to
use "if [[ "$_i_line[2]" = (complete-word|delete-char-or-list|etc.etc.) ]]",
but not as readable/maintainable IMO.

Note use of the relatively new fall-through case syntax. One thing this
shows is that case statements still don't know how to xtrace themselves, so
leaving it the slower way might be preferable during debugging.

In one other case, I pulled a test that expands a variable but doesn't rely
on the loop variable out of the loop.  Probably not terribly significant as
that loop doesn't run all that many cycles, but what the heck.

Index: Completion/Core/compinit
===================================================================
RCS file: /extra/cvsroot/zsh/zsh-3.1/Completion/Core/compinit,v
retrieving revision 1.5
diff -u -r1.5 compinit
--- compinit	1999/04/20 16:13:52	1.5
+++ compinit	1999/05/03 01:00:23
@@ -180,9 +180,15 @@
     *)
       # For commands store the function name in the `_comps'
       # associative array, command names as keys.
-      for i; do
-        [[ -z "$new" || "${+_comps[$i]}" -eq 0 ]] && _comps[$i]="$func"
-      done
+      if [[ -z "$new" ]]; then
+	for i; do
+	  _comps[$i]="$func"
+	done
+      else
+        for i; do
+          [[ "${+_comps[$i]}" -eq 0 ]] && _comps[$i]="$func"
+        done
+      fi
       ;;
     esac
   else
@@ -286,31 +292,36 @@
       read -rA _i_line < $_i_file
       _i_tag=$_i_line[1]
       shift _i_line
-      if [[ $_i_tag = '#compdef' ]]; then
+      case $_i_tag in
+      (\#compdef)
 	if [[ $_i_line[1] = -[pk] ]]; then
 	  compdef ${_i_line[1]}a "${_i_file:t}" "${(@)_i_line[2,-1]}"
 	else
 	  compdef -na "${_i_file:t}" "${_i_line[@]}"
 	fi
-      elif [[ $_i_tag = '#autoload' ]]; then
+	;;
+      (\#autoload)
 	autoload ${_i_file:t}
-      fi
+	;;
+      esac
     done
   done
 
   bindkey |
     while read -rA _i_line; do
-      if [[ "$_i_line[2]" = complete-word ||
-	"$_i_line[2]" = delete-char-or-list ||
-	"$_i_line[2]" = expand-or-complete ||
-	"$_i_line[2]" = expand-or-complete-prefix ||
-	"$_i_line[2]" = list-choices ||
-	"$_i_line[2]" = menu-complete ||
-	"$_i_line[2]" = menu-expand-or-complete ||
-	"$_i_line[2]" = reverse-menu-complete ]]; then
+      case "$_i_line[2]" in
+      (complete-word) ;&
+      (delete-char-or-list) ;&
+      (expand-or-complete) ;&
+      (expand-or-complete-prefix) ;&
+      (list-choices) ;&
+      (menu-complete) ;&
+      (menu-expand-or-complete) ;&
+      (reverse-menu-complete)
 	zle -C _complete_$_i_line[2] $_i_line[2] _main_complete
 	bindkey "${_i_line[1][2,-2]}" _complete_$_i_line[2]
-      fi
+	;;
+      esac
     done
 
   unset _i_dir _i_line _i_file _i_tag

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com