'main': Use zsh/parameter instead of type -w

If possible, try to use the zsh/parameter module to get
information about a shell words.

This avoids subshells and is a huge speed improvement
on systems such as cygwin.

Note 1:
$commands does not know about PATH_DIRS. So in case
PATH_DIRS is set, 'type -w' is still used if nothing
else matches.

Note 2:
zsh/parameter can't distinguish between 'command' and
'hashed'. Adjusted the test for that case to XFAIL.

The ideal solution would be if whence had an option to
put the result in REPLY instead of printing it to stdout.

highlighters/main/main-highlighter.zsh

@@ -80,17 +80,39 @@ _zsh_highlight_main_add_region_highlight() {
   _zsh_highlight_add_highlight $start $end "$@"
 }
 
-# Wrapper around 'type -w'.
+# Get the type of a command.
 #
-# Takes a single argument and outputs the output of 'type -w $1'.
+# Uses the zsh/parameter module if available to avoid forks, and a
+# wrapper around 'type -w' as fallback.
 #
-# NOTE: This runs 'setopt', but that should be safe since it'll only ever be
-# called inside a $(...) subshell, so the effects will be local.
+# Takes a single argument.
+#
+# The result will be stored in REPLY.
 _zsh_highlight_main__type() {
   if (( $#options_to_set )); then
     setopt localoptions $options_to_set;
   fi
-  LC_ALL=C builtin type -w -- $1 2>/dev/null
+  unset REPLY
+  if zmodload -e zsh/parameter; then
+    if (( $+aliases[(e)$1] )); then
+      REPLY=alias
+    elif (( $+saliases[(e)${1##*.}] )); then
+      REPLY='suffix alias'
+    elif (( $reswords[(Ie)$1] )); then
+      REPLY=reserved
+    elif (( $+functions[(e)$1] )); then
+      REPLY=function
+    elif (( $+builtins[(e)$1] )); then
+      REPLY=builtin
+    elif (( $+commands[(e)$1] )); then
+      REPLY=command
+    elif ! builtin type -w -- $1 >/dev/null 2>&1; then
+      REPLY=none
+    fi
+  fi
+  if ! (( $+REPLY )); then
+    REPLY="${$(LC_ALL=C builtin type -w -- $1 2>/dev/null)#*: }"
+  fi
 }
 
 # Check whether the first argument is a redirection operator token.
@@ -329,7 +351,8 @@ _zsh_highlight_main_highlighter()
      else
       _zsh_highlight_main_highlighter_expand_path $arg
       local expanded_arg="$REPLY"
-      local res="$(_zsh_highlight_main__type ${expanded_arg})"
+      _zsh_highlight_main__type ${expanded_arg}
+      local res="$REPLY"
       () {
         # Special-case: command word is '$foo', like that, without braces or anything.
         #
@@ -339,17 +362,16 @@ _zsh_highlight_main_highlighter()
         # parameters that refer to commands, functions, and builtins.
         local -a match mbegin mend
         local MATCH; integer MBEGIN MEND
-        if [[ $res == *': none' ]] && (( ${+parameters} )) &&
+        if [[ $res == none ]] && (( ${+parameters} )) &&
            [[ ${arg[1]} == \$ ]] && [[ ${arg:1} =~ ^([A-Za-z_][A-Za-z0-9_]*|[0-9]+)$ ]]; then
-          res="$(_zsh_highlight_main__type ${(P)MATCH})"
+          _zsh_highlight_main__type ${(P)MATCH}
+          res=$REPLY
         fi
       }
       case $res in
-        *': reserved')  style=reserved-word;;
-        *': suffix alias')
-                        style=suffix-alias
-                        ;;
-        *': alias')     () {
+        reserved)       style=reserved-word;;
+        'suffix alias') style=suffix-alias;;
+        alias)          () {
                           integer insane_alias
                           case $arg in 
                             # Issue #263: aliases with '=' on their LHS.
@@ -373,11 +395,11 @@ _zsh_highlight_main_highlighter()
                           fi
                         }
                         ;;
-        *': builtin')   style=builtin;;
-        *': function')  style=function;;
-        *': command')   style=command;;
-        *': hashed')    style=hashed-command;;
-        *)              if _zsh_highlight_main_highlighter_check_assign; then
+        builtin)        style=builtin;;
+        function)       style=function;;
+        command)        style=command;;
+        hashed)         style=hashed-command;;
+        none)           if _zsh_highlight_main_highlighter_check_assign; then
                           style=assign
                           if [[ $arg[-1] == '(' ]]; then
                             in_array_assignment=true
@@ -431,6 +453,9 @@ _zsh_highlight_main_highlighter()
                           fi
                         fi
                         ;;
+        *)              _zsh_highlight_main_add_region_highlight commandtypefromthefuture-$res
+                        already_added=1
+                        ;;
       esac
      fi
     else # $arg is a non-command word

highlighters/main/test-data/hashed-command.zsh

@@ -31,5 +31,5 @@ hash zsh_syntax_highlighting_hash=/doesnotexist
 BUFFER='zsh_syntax_highlighting_hash'
 
 expected_region_highlight=(
-  "1 28 hashed-command"
+  "1 28 hashed-command 'zsh/parameter cannot distinguish between hashed and command'"
 )