[ ParseToken__ given_ttype given_tdata token_n
             token l o i j k and_parity single_object desc_wn many_flag
             token_allows_multiple;

!  **** (A) ****

   token_filter = 0;

   switch(given_ttype)
   {   ELEMENTARY_TT:
           switch(given_tdata)
           {   SPECIAL_TOKEN:
                   l=TryNumber(wn);
                   special_word=NextWord();
                   #ifdef DEBUG;
                   if (l~=-1000)
                       if (parser_trace>=3)
                           print "  [Read special as the number ", l, "]^";
                   #endif;
                   if (l==-1000)
                   {   #ifdef DEBUG;
                       if (parser_trace>=3)
                         print "  [Read special word at word number ", wn, "]^";
                       #endif;
                       l = special_word;
                   }
                   parsed_number = l; return GPR_NUMBER;

               NUMBER_TOKEN:
                   l=TryNumber(wn++);
                   if (l==-1000) { etype=NUMBER_PE; return GPR_FAIL; }
                   #ifdef DEBUG;
                   if (parser_trace>=3) print "  [Read number as ", l, "]^";
                   #endif;
                   parsed_number = l; return GPR_NUMBER;

               CREATURE_TOKEN:
                   if (action_to_be==##Answer or ##Ask or ##AskFor or ##Tell)
                       scope_reason = TALKING_REASON;

               TOPIC_TOKEN:
                   consult_from = wn;
                   if ((line_ttype-->(token_n+1) ~= PREPOSITION_TT)
                       && (line_token-->(token_n+1) ~= ENDIT_TOKEN))
                       RunTimeError(13);
                   do o=NextWordStopped();
                   until (o==-1 || PrepositionChain(o, token_n+1) ~= -1);
                   wn--;
                   consult_words = wn-consult_from;
                   if (consult_words==0) return GPR_FAIL;
                   if (action_to_be==##Ask or ##Answer or ##Tell)
                   {   o=wn; wn=consult_from; parsed_number=NextWord();
                       #IFDEF EnglishNaturalLanguage;
                       if (parsed_number=='the' && consult_words>1)
                           parsed_number=NextWord();
                       #ENDIF;
                       wn=o; return 1;
                   }
                   return GPR_PREPOSITION;
           }

       PREPOSITION_TT:
           #Iffalse Grammar__Version==1;
!  Is it an unnecessary alternative preposition, when a previous choice
!  has already been matched?
           if ((token->0) & $10) return GPR_PREPOSITION;
           #Endif;

!  If we've run out of the player's input, but still have parameters to
!  specify, we go into "infer" mode, remembering where we are and the
!  preposition we are inferring...

           if (wn > num_words)
           {   if (inferfrom==0 && parameters<params_wanted)
               {   inferfrom = pcount; inferword = token;
                   pattern-->pcount = REPARSE_CODE + Dword__No(given_tdata);
               }

!  If we are not inferring, then the line is wrong...

               if (inferfrom==0) return -1;

!  If not, then the line is right but we mark in the preposition...

               pattern-->pcount = REPARSE_CODE + Dword__No(given_tdata);
               return GPR_PREPOSITION;
           }

           o = NextWord();

           pattern-->pcount = REPARSE_CODE + Dword__No(o);

!  Whereas, if the player has typed something here, see if it is the
!  required preposition... if it's wrong, the line must be wrong,
!  but if it's right, the token is passed (jump to finish this token).

           if (o == given_tdata) return GPR_PREPOSITION;
           #Iffalse Grammar__Version==1;
           if (PrepositionChain(o, token_n) ~= -1)
               return GPR_PREPOSITION;
           #Endif;
           return -1;

       GPR_TT:
           l=indirect(given_tdata);
           #ifdef DEBUG;
           if (parser_trace>=3)
               print "  [Outside parsing routine returned ", l, "]^";
           #endif;
           return l;

       SCOPE_TT:
           scope_token = given_tdata;
           scope_stage = 1;
           l = indirect(scope_token);
           #ifdef DEBUG;
           if (parser_trace>=3)
               print "  [Scope routine returned multiple-flag of ", l, "]^";
           #endif;
           if (l==1) given_tdata = MULTI_TOKEN; else given_tdata = NOUN_TOKEN;

       ATTR_FILTER_TT:
           token_filter = 1 + given_tdata;
           given_tdata = NOUN_TOKEN;

       ROUTINE_FILTER_TT:
           token_filter = given_tdata;
           given_tdata = NOUN_TOKEN;
   }

   token = given_tdata;

!  **** (B) ****

!  There are now three possible ways we can be here:
!      parsing an elementary token other than "special" or "number";
!      parsing a scope token;
!      parsing a noun-filter token (either by routine or attribute).
!
!  In each case, token holds the type of elementary parse to
!  perform in matching one or more objects, and
!  token_filter is 0 (default), an attribute + 1 for an attribute filter
!  or a routine address for a routine filter.

   token_allows_multiple = false;
   if (token == MULTI_TOKEN or MULTIHELD_TOKEN or MULTIEXCEPT_TOKEN
                or MULTIINSIDE_TOKEN) token_allows_multiple = true;

   many_flag = false; and_parity = true; dont_infer = false;

!  **** (C) ****
!  We expect to find a list of objects next in what the player's typed.

  .ObjectList;

   #ifdef DEBUG;
   if (parser_trace>=3) print "  [Object list from word ", wn, "]^";
   #endif;

!  Take an advance look at the next word: if it's "it" or "them", and these
!  are unset, set the appropriate error number and give up on the line
!  (if not, these are still parsed in the usual way - it is not assumed
!  that they still refer to something in scope)

    o=NextWord(); wn--;

    pronoun_word = NULL; pronoun_obj = NULL;
    l = PronounValue(o);
    if (l ~= 0)
    {   pronoun_word = o; pronoun_obj = l;
        if (l == NULL)
        {   !   Don't assume this is a use of an unset pronoun until the
            !   descriptors have been checked, because it might be an
            !   article (or some such) instead

            for (l=1:l<=LanguageDescriptors-->0:l=l+4)
                if (o == LanguageDescriptors-->l) jump AssumeDescriptor;
            pronoun__word=pronoun_word; pronoun__obj=pronoun_obj;
            etype=VAGUE_PE; return GPR_FAIL;
        }
    }

    .AssumeDescriptor;

    if (o==ME1__WD or ME2__WD or ME3__WD)
    {   pronoun_word = o; pronoun_obj = player;
    }

    allow_plurals = true; desc_wn = wn;

    .TryAgain;
!   First, we parse any descriptive words (like "the", "five" or "every"):
    l = Descriptors(token_allows_multiple);
    if (l~=0) { etype=l; return GPR_FAIL; }

    .TryAgain2;

!  **** (D) ****

!  This is an actual specified object, and is therefore where a typing error
!  is most likely to occur, so we set:

    oops_from = wn;

!  So, two cases.  Case 1: token not equal to "held" (so, no implicit takes)
!  but we may well be dealing with multiple objects

!  In either case below we use NounDomain, giving it the token number as
!  context, and two places to look: among the actor's possessions, and in the
!  present location.  (Note that the order depends on which is likeliest.)

    if (token ~= HELD_TOKEN)
    {   i=multiple_object-->0;
        #ifdef DEBUG;
        if (parser_trace>=3)
            print "  [Calling NounDomain on location and actor]^";
        #endif;
        l=NounDomain(actors_location, actor, token);
        if (l==REPARSE_CODE) return l;                  ! Reparse after Q&A
        if (l==0) {   if (indef_possambig)
                      {   ResetDescriptors(); wn = desc_wn; jump TryAgain2; }
                      etype=CantSee(); jump FailToken; } ! Choose best error

        #ifdef DEBUG;
        if (parser_trace>=3)
        {   if (l>1)
                print "  [ND returned ", (the) l, "]^";
            else
            {   print "  [ND appended to the multiple object list:^";
                k=multiple_object-->0;
                for (j=i+1:j<=k:j++)
                    print "  Entry ", j, ": ", (The) multiple_object-->j,
                          " (", multiple_object-->j, ")^";
                print "  List now has size ", k, "]^";
            }
        }
        #endif;

        if (l==1)
        {   if (~~many_flag)
            {   many_flag = true;
            }
            else                                  ! Merge with earlier ones
            {   k=multiple_object-->0;            ! (with either parity)
                multiple_object-->0 = i;
                for (j=i+1:j<=k:j++)
                {   if (and_parity) MultiAdd(multiple_object-->j);
                    else MultiSub(multiple_object-->j);
                }
                #ifdef DEBUG;
                if (parser_trace>=3)
                    print "  [Merging ", k-i, " new objects to the ",
                        i, " old ones]^";
                #endif;
            }
        }
        else
        {   ! A single object was indeed found

            if (match_length == 0 && indef_possambig)
            {   !   So the answer had to be inferred from no textual data,
                !   and we know that there was an ambiguity in the descriptor
                !   stage (such as a word which could be a pronoun being
                !   parsed as an article or possessive).  It's worth having
                !   another go.

                ResetDescriptors(); wn = desc_wn; jump TryAgain2;
            }
        
            if (token==CREATURE_TOKEN && CreatureTest(l)==0)
            {   etype=ANIMA_PE; jump FailToken; } !  Animation is required

            if (~~many_flag)
                single_object = l;
            else
            {   if (and_parity) MultiAdd(l); else MultiSub(l);
                #ifdef DEBUG;
                if (parser_trace>=3)
                    print "  [Combining ", (the) l, " with list]^";
                #endif;
            }
        }
    }

!  Case 2: token is "held" (which fortunately can't take multiple objects)
!  and may generate an implicit take

    else

    {   l=NounDomain(actor,actors_location,token);       ! Same as above...
        if (l==REPARSE_CODE) return GPR_REPARSE;
        if (l==0)
        {   if (indef_possambig)
            {   ResetDescriptors(); wn = desc_wn; jump TryAgain2; }
            etype=CantSee(); return GPR_FAIL;            ! Choose best error
        }

!  ...until it produces something not held by the actor.  Then an implicit
!  take must be tried.  If this is already happening anyway, things are too
!  confused and we have to give up (but saving the oops marker so as to get
!  it on the right word afterwards).
!  The point of this last rule is that a sequence like
!
!      > read newspaper
!      (taking the newspaper first)
!      The dwarf unexpectedly prevents you from taking the newspaper!
!
!  should not be allowed to go into an infinite repeat - read becomes
!  take then read, but take has no effect, so read becomes take then read...
!  Anyway for now all we do is record the number of the object to take.

        o=parent(l);
        if (o~=actor)
        {   if (notheld_mode==1)
            {   saved_oops=oops_from; etype=NOTHELD_PE; jump FailToken;
            }
            not_holding = l;
            #ifdef DEBUG;
            if (parser_trace>=3)
                print "  [Allowing object ", (the) l, " for now]^";
            #endif;
        }
        single_object = l;
    }

!  The following moves the word marker to just past the named object...

    wn = oops_from + match_length;

!  **** (E) ****

!  Object(s) specified now: is that the end of the list, or have we reached
!  "and", "but" and so on?  If so, create a multiple-object list if we
!  haven't already (and are allowed to).

    .NextInList;

    o=NextWord();

    if (o==AND1__WD or AND2__WD or AND3__WD or BUT1__WD or BUT2__WD or BUT3__WD
           or comma_word)
    {
        #ifdef DEBUG;
        if (parser_trace>=3) print "  [Read connective '", (address) o, "']^";
        #endif;

        if (~~token_allows_multiple)
        {   etype=MULTI_PE; jump FailToken;
        }

        if (o==BUT1__WD or BUT2__WD or BUT3__WD) and_parity = 1-and_parity;

        if (~~many_flag)
        {   multiple_object-->0 = 1;
            multiple_object-->1 = single_object;
            many_flag = true;
            #ifdef DEBUG;
            if (parser_trace>=3)
                print "  [Making new list from ", (the) single_object, "]^";
            #endif;
        }
        dont_infer = true; inferfrom=0;           ! Don't print (inferences)
        jump ObjectList;                          ! And back around
    }

    wn--;   ! Word marker back to first not-understood word

!  **** (F) ****

!  Happy or unhappy endings:

    .PassToken;

    if (many_flag)
    {   single_object = GPR_MULTIPLE;
        multi_context = token;
    }
    else
    {   if (indef_mode==1 && indef_type & PLURAL_BIT ~= 0)
        {   if (indef_wanted<100 && indef_wanted>1)
            {   multi_had=1; multi_wanted=indef_wanted;
                etype=TOOFEW_PE;
                jump FailToken;
            }
        }
    }
    return single_object;

    .FailToken;

!  If we were only guessing about it being a plural, try again but only
!  allowing singulars (so that words like "six" are not swallowed up as
!  Descriptors)

    if (allow_plurals && indef_guess_p==1)
    {   allow_plurals=false; wn=desc_wn; jump TryAgain;
    }
    return -1;
];