[Optparsing] Support options in whatever position

However, it has a precondition that developers MUST respect:
  An option CAN'T have differente meanings/behaviour in different subcommands.
  For example, "-s" means "size" and accept an argument. If you are tempted to add
  an option "-s" (that means, for example "silent", and doesn't accept an argument)
This, however, make sense even from an usability point of view.
Also, option with optional argument are prohibited.

The technique is a "double scan": first, we scan options passing
_every_ possible subcommand options to zparseopts.
This way, we can distinguish between option argument and parameters.
So, we recognize which is the subcommand.
Then, parse again

src/tomb

@@ -1066,64 +1066,58 @@ EOF
     act "Tomb is now installed."
 }
 
-main () {
-    typeset -A subcommands_opts
+main() {
+    local -A subcommands_opts
     ### Options configuration
+    #Hi, dear developer! Are you trying to add a new subcommand, or to add some options?
+    #Well, keep in mind that:
+    # 1. An option CAN'T have differente meanings/behaviour in different subcommands.
+    #    For example, "-s" means "size" and accept an argument. If you are tempted to add
+    #    an option "-s" (that means, for example "silent", and doesn't accept an argument)
+    #              DON'T DO IT!
+    #     There are two reasons for that:
+    #       I. usability; user expect that "-s" is "size
+    #       II. Option parsing WILL EXPLODE if you do this kind of bad things
+    #               (it will say "option defined more than once, and he's right)
     main_opts=(q -quiet=q D -debug=D h -help=h v -verbose=v)
     subcommands_opts[open]="n -nohook=n k: -key=k o: -mount-options=o"
     subcommands_opts[mount]=${subcommands_opts[open]}
     subcommands_opts[create]="s: -size=s"
     subcommands_opts[close]=""
     subcommands_opts[help]=""
-    subcommand_opts[slam]=""
-    subcommand_opts[list]=""
-    subcommand_opts[help]=""
-    subcommand_opts[bury]=""
-    subcommand_opts[exhume]=""
-    subcommand_opts[decompose]=""
-    subcommand_opts[recompose]=""
-    subcommand_opts[install]=""
-    subcommand_opts[askpass]=""
-    subcommand_opts[mktemp]=""
-  ### Parsing global options (wherever they are)
-  zparseopts -M -E -D -Aglobal_opts $main_opts
-  if [[ -n ${(k)global_opts[-h]} ]]; then # -h is set
-	usage
-	exit 0
-  fi
-
-  if [[ $? != 0 ]]; then
-	error Some error occurred during option processing. See tomb help for more info
-	exit 127
-  fi
-  typeset -a pars
-  set -A pars $*
-  typeset -g subcommand
-  subcommand=''
-  for arg in $*; do
-	if [[ $arg[1] != '-' ]]; then
-	  subcommand=$arg
-	  valid=0
-      if [[ -z ${(k)subcommands_opts[$subcommand]} ]]; then #command not set
-		echo "Subcommand $subcommand is not valid; see tomb help"
-		exit 126
-	  fi
-	  pars[${(k)*[(r)$arg]}]=()
-	  break
-	fi
-  done
-  set -- $pars
-    if [[ -z $subcommand ]]; then
-        error You have to specify some subcommand
-        exit 126
+    subcommands_opts[slam]=""
+    subcommands_opts[list]=""
+    subcommands_opts[help]=""
+    subcommands_opts[bury]=""
+    subcommands_opts[exhume]=""
+    subcommands_opts[decompose]=""
+    subcommands_opts[recompose]=""
+    subcommands_opts[install]=""
+    subcommands_opts[askpass]=""
+    subcommands_opts[mktemp]=""
+    ### Detect subcommand
+    local -aU every_opts #every_opts behave like a set; that is, an array with unique elements
+    for optspec in $subcommands_opts$main_opts; do
+        for opt in ${=optspec}; do
+            every_opts+=${opt}
+        done
+    done
+    local -a oldstar
+    oldstar=($argv)
+    zparseopts -M -E -D -Adiscardme ${every_opts}
+    unset discardme
+    subcommand=$1
+    if [[ -z ${(k)subcommands_opts[$subcommand]} ]]; then #there's no such subcommand
+        error "Subcommand '$subcommand' doesn't exist"
+        exit 127
     fi
-  ### End global options
+    argv=(${oldstar})
+    unset oldstar
 
-
-  ### Parsing command-specific options
+  ### Parsing global + command-specific options
   # zsh magic: ${=string} will split to multiple arguments when spaces occur
-  set -A cmd_opts ${=subcommands_opts[$subcommand]}
-  if [[ -n $cmd_opts ]]; then
+  set -A cmd_opts ${main_opts} ${=subcommands_opts[$subcommand]}
+  if [[ -n $cmd_opts ]]; then #if there is no option, we don't need parsing
         zparseopts -M -E -D -Aopts ${cmd_opts}
 	if [[ $? != 0 ]]; then
 	  error "Some error occurred during option processing. See \"tomb help\" for more info"
@@ -1139,7 +1133,7 @@ main () {
 	  continue #it shouldnt be appended to PARAM
 	elif [[ $arg[1] == '-'  ]]; then
 	  if [[ $ok == 0 ]]; then
-		echo ERROR: unrecognized option $arg >&2
+		error "unrecognized option $arg"
 		exit 127
 	  fi
 	fi