Add special RST roles for the Inform entities.

[ibg.git] / chapters / 13.rst

===========================
Captain Fate: the final cut
===========================

.. epigraph::

   | |CENTER| *Y was a youth, that did not love school;*
   | |CENTER| *Z was a zany, a poor harmless fool.*

.. only:: html

   .. image:: /images/picY.png
      :align: left

|Y|\ou'll probably be pleased to hear that Captain Fate has almost run his
allotted span. There are some minor objects still to be defined -- the
toilet, our hero’s clothes, the all-important costume -- but first we need
to decorate the café a little more.

Additional catering garnish
===========================

We must not forget a couple of tiny details in the café room:

.. code-block:: inform

  Object   food "Benny's snacks" cafe
    with   name 'food' 'pastry' 'pastries' 'sandwich' 'sandwiches' 'snack'
           before [; "There is no time for FOOD right now."; ],
    has    scenery proper;

  Object   menu "menu" cafe
    with   name 'informative' 'menu' 'board' 'picture' 'writing',
           description
               "The menu board lists Benny's food and drinks, along with their
                prices. Too bad you've never learnt how to read, but luckily
                there is a picture of a big cup of coffee among the
                incomprehensible writing.",
           before [;
             Take:
               "The board is mounted on the wall behind Benny. Besides, it's
                useless WRITING.";
           ],
    has    scenery;

And a not-so-trivial object:

.. code-block:: inform

  Object  coffee "cup of coffee" benny
    with  name 'cup' 'of' 'coffee' 'steaming' 'cappuccino'
               'cappucino' 'capuccino' 'capucino',
          description [;
              if (self in benny)
                  "The picture on the menu board SURE looks good.";
              else
                  "It smells delicious.";
          ],
          before [;
            Take,Drink,Taste:
              if (self in benny) "You should ask Benny for one first.";
              else {
                  move self to benny;
                  print "You pick up the cup and swallow a mouthful. Benny's
                         WORLDWIDE REPUTATION is well deserved. Just as you
                         finish, Benny takes away the empty cup.";
                  if (benny.coffee_not_paid == true)
                      " ~That will be one quidbuck, sir.~";
                  else
                      "";
              }
            Buy:
              if (coin in player) <<Give coin benny>>;
              else                "You have no money.";
            Smell:
              "If your HYPERACTIVE pituitary glands are to be trusted,
               it's Colombian.";
          ];

There's nothing really new in this object (other than that the :prop:`name` 
property caters for orthographically challenged players), but notice how 
we don't ``remove`` it after the player drinks it. In an apparently 
absurd whim, the coffee returns to Benny magically (although this is not 
information that the player needs to know). Why? After you remove an 
object from the game, if the player attempts, say, to EXAMINE it, the 
interpreter will impertinently state that "You can't see any such 
thing". Moreover, if the player asks Benny for a second coffee, once the 
first one has been removed, Benny will complain "I don’t think that’s on 
the menu, sir" -- a blatant lie -- which was the default in Benny’s 
orders property. Since the removed coffee object does not belong to 
Benny, it's not a noun that the player can ASK Benny FOR. By making it a 
child of the barman (who has the :attr:`transparent` attribute set), the 
coffee is still an object that players can refer to. We ensure that they 
don't get more cups thanks to Benny's ``coffee_asked_for`` property, 
which will remain :const:`true` after the first time.

We also ensure that Benny doesn't ask for money from players who have 
already paid, by first printing a "You pick up the cup..." message and 
then testing Benny's ``coffee_not_paid`` property. If its value is 
:const:`true`, we can finish the message with the "quidbuck" print-and-return 
statement. If its value is :const:`false`, the player has previously paid, 
and so there's nothing else to say. However, we still need to terminate 
the incomplete message with a newline, and to return :const:`true` from the 
property routine; we *could* have used the statements ``{ print "^"; 
return true; }``, but an empty ``""`` statement does the same thing more 
neatly.


Toilet or dressing room?
========================

Rather more of the latter, actually, since it's the only place away from 
curious eyes where our hero will be able to metamorphose from weakling 
into the bane of all evildoers. And we *really* don't want to become, 
erm, bogged down with details of the room's function or plumbing.

There's not a lot about the toilet room and its contents, though there 
will be some tricky side effects:

.. code-block:: inform

  Room    toilet "Unisex toilet"
    with  description
              "A surprisingly CLEAN square room covered with glazed-ceramic
               tiles, featuring little more than a lavatory and a light switch.
               The only exit is south, through the door and into the cafe.",
          s_to toilet_door,
    has   ~light scored;

  Appliance lavatory "lavatory" toilet
    with name 'lavatory' 'wc' 'toilet' 'loo' 'bowl' 'can' 'john' 'bog',
         before [;
           Examine,Search,LookUnder:
             if (coin in self) {
                 move coin to parent(self);
                 "The latest user CIVILLY flushed it after use, but failed to
                  pick up the VALUABLE coin that fell from his pants.";
             }
           Receive:
             "While any other MORTALS might unwittingly throw just about
              ANYTHING into ", (the) self, ", you remember the WISE teachings
              of your mentor, Duke ELEGANT, about elderly plumbing and rising
              waters.";
         ];

  Object  coin "valuable coin" lavatory
    with  name 'valuable' 'coin' 'silver' 'quidbuck',
          description "It's a genuine SILVER QUIDBUCK.",
          before [;
            Drop:
              if (self notin player) return false;
              "Such a valuable coin? Har, har! This must be a demonstration of
               your ULTRA-FLIPPANT jesting!";
          ],
          after [;
            Take:
              "You crouch into the SLEEPING DRAGON position and deftly, with
               PARAMOUNT STEALTH, you pocket the lost coin.";
          ],
    has   scored;

We initially place the coin as a child of the lavatory (just so that we 
can easily make the ``if (coin in self)`` one-time test). Since the 
lavatory does not have the :attr:`transparent` attribute set, the coin will 
be invisible to players until they try to inspect the lavatory, an 
action that will move the coin into the toilet room. Once taken, the 
coin will remain in the inventory until the player gives it to Benny, 
because we trap any ``Drop`` actions to help the player to Do the Right 
Thing.

The lavatory object includes a load of helpful synonyms in its name 
property, including our favourite word ``'toilet'`` . That won't be a 
problem: the other objects here which may have TOILET in their names -- 
the key and the door -- both use the ``pname`` property to turn their 
use of ``'toilet'`` into a lower-priority adjective.

See that here we have the only two :attr:`scored` attributes of the game. 
The player will be awarded one point for entering the toilet room, and 
another for finding and picking up the coin.

You might have noticed that we are forcefully clearing the :attr:`light` 
attribute, inherited from the ``Room`` class. This will be a windowless 
space and, to add a touch of realism, we'll make the room a dark one, 
which will enable us to tell you about Inform's default behaviour when 
there's no light to see by. However, let's define first the light switch 
mentioned in the room's description to aid players in their dressing 
duties.

.. code-block:: inform

  Appliance  light_switch "light switch" toilet
    with     name 'light' 'switch',
             description
                 "A notorious ACHIEVEMENT of technological SCIENCE, elegant yet
                  EASY to use.",
             before [;
               Push:
                 if (self has on) <<SwitchOff self>>;
                 else             <<SwitchOn  self>>;
             ],
             after [;
               SwitchOn:
                 give self light;
                 "You turn on the light in the toilet.";
               SwitchOff:
                 give self ~light;
                 "You turn off the light in the toilet.";
             ],
    has      switchable ~on;

Please notice the appearance of new attributes :attr:`switchable` and 
:attr:`on`. switchable enables the object to be turned on and off, and is 
typical of lanterns, computers, television sets, radios, and so on. The 
library automatically extends the description of these objects by 
indicating if they are currently on or off:

.. code-block:: transcript

  > X LIGHT SWITCH
  A notorious ACHIEVEMENT of technological SCIENCE, elegant yet EASY to use.
  The light switch is currently switched on.

Two new actions are ready to use, ``SwitchOn`` and ``SwitchOff``. Left 
to themselves, they toggle the object's state between ON and OFF and 
display a message like:

.. code-block:: transcript

  You switch the brass lantern on.

They also take care of checking if the player fumbled and tried to turn 
on (or off) an object which was already on (or off). How does the 
library know the state of the object? This is thanks to the :attr:`on` 
attribute, which is set or cleared automatically as needed. You can, of 
course, set or clear it manually like any other attribute, with the 
``give`` statement:

.. code-block:: inform

  give self on;

  give self ~on;

and check if a :attr:`switchable` object is on or off with the test:

.. code-block:: inform

  if (light_switch has on) ...

  if (light_switch hasnt on) ...

A :attr:`switchable` object is OFF by default. However, you’ll notice that 
the has line of the object definition includes ``~on`` :

.. code-block:: inform

  has    switchable ~on;

Surely that’s saying "not-on"? Surely that's what would have happened 
anyway if the line hadn't mentioned the attribute at all?

.. code-block:: inform

  has    switchable;

Absolutely true. Adding that ``~on`` attribute has no effect whatsoever 
on the game -- but nevertheless it's a good idea. It's an aide-mémoire, 
a way of reminding ourselves that we start with the attribute clear, and 
that at some point we'll be setting it for some purpose. Trust us: it's 
worthwhile taking tiny opportunities like this to help yourself.

Let’s see how our light switch works. We trap the ``SwitchOn`` and 
``SwitchOff`` actions in the :prop:`after` property (when the switching has 
successfully taken place) and use them to give :attr:`light` to the light 
switch.

Uh, wait. To the light switch? Why not to the toilet room? Well, there's 
a reason and we'll see it in a minute. For now, just remember that, in 
order for players to see their surroundings, you need only one object in 
a room with the :attr:`light` attribute set. It doesn't have to be the room 
itself (though this is usually convenient).

After setting the :attr:`light` attribute, we display a customised message, 
to avoid the default:

.. code-block:: transcript

  You switch the light switch on.

which, given the name of the object, doesn't read very elegantly. We 
foresee that players might try to PUSH SWITCH, so we trap this attempt 
in a :prop:`before` property and redirect it to ``SwitchOn`` and 
``SwitchOff`` actions, checking first which one is needed by testing the 
:attr:`on` attribute. Finally, we have made the switch a member of the class 
``Appliance``, so that the player doesn't walk away with it.

.. note::

  Remember what we said about class inheritance? No matter what you 
  define in the class, the object’s definition has priority. The class 
  ``Appliance`` defines a response for the ``Push`` action, but we 
  override it here with a new behaviour.


And there was light
===================

So the player walks into the toilet and

.. code-block:: transcript

  Darkness
  It is pitch dark, and you can't see a thing.

Oops! No toilet description, no mention of the light switch, nothing. It 
is reasonable to think that if we have opened the toilet door to access 
the toilet, some light coming from the café room will illuminate our 
surroundings -- at least until the player decides to close the door. So 
perhaps it would be a good idea to append a little code to the door 
object to account for this. A couple of lines in the after property will 
suffice:

.. code-block:: inform

  after [ ks;
    Unlock:
      if (self has locked) return false;
      print "You unlock ", (the) self, " and open it.^";
      ks = keep_silent; keep_silent = true;
      <Open self>; keep_silent = ks;
      return true;
    Open:
      give toilet light;
    Close:
      give toilet ~light;

  ],

And this is the reason why the light switch didn't set the :attr:`light` 
attribute of the toilet room, but did it to itself. We avoid running 
into trouble if we let the open/closed states of the door control the 
light of the room object, and the on/off states of the switch control 
the light of the switch. So it is one shiny light switch. Fortunately, 
players are never aware of this glowing artefact.

.. note::

  Now, could they? Well, if players could TAKE the light switch (which
  we have forbidden) and then did INVENTORY, the trick would be given
  away, because all objects with the :attr:`light` attribute set are listed 
  as ``(providing light)`` .

So the player walks into the toilet and

.. code-block:: transcript

  Unisex toilet
  A surprisingly CLEAN square room covered with glazed-ceramic tiles, featuring
  little more than a lavatory and a light switch. The only exit is south, through
  the door and into the cafe.

  [Your score has just gone up by one point.]

Better. Now, suppose the player closes the door.

.. code-block:: transcript

  >CLOSE DOOR
  You close the door to the cafe.

  It is now pitch dark in here!

The player might try then to LOOK:

Well, no problem. We have mentioned that there is a light switch. Surely 
the player will now try to:

.. code-block:: transcript

  >TURN ON LIGHT SWITCH
  You can't see any such thing.

Oops! Things are getting nasty here in the dark. It's probably time to 
leave this place and try another approach:

.. code-block:: transcript

  >OPEN DOOR
  You can't see any such thing.

And this illustrates one of the terrible things about darkness in a 
game. You can't see anything; you can do very little indeed. All objects 
except those in your inventory are out of scope, unreachable, as if 
non-existent. Worse, if you DROP one of the objects you are carrying, it 
will be swallowed by the dark, never to be found until there is light to 
see by.

The player, who is doubtless immersed in the fantasy of the game, will 
now be a little annoyed. "I am in a small bathroom and I can't even 
reach the door I have just closed?" The player's right, of 
course [#dark]_.  Darkened rooms are one cliché of traditional games. 
Usually you move in one direction while looking for treasure in some 
underground cave, and suddenly arrive at a pitch black place. It's good 
behaviour of the game to disallow exploration of unknown dark territory, 
and it's a convention to bar passage to players until they return with a 
light source. However, if the scenario of the game features, say, the 
player character's home, a little apartment with two rooms, and there’s 
no light in the kitchen, we could expect the owner of the house to know 
how to move around a little, perhaps groping for the light switch or 
even going to the refrigerator in the dark.

We are in a similar situation. The inner logic of the game demands that 
blind players should be able to open the door and probably operate the 
light switch they've just encountered. We have been telling you that an 
object is in scope when it’s in the same room as the player. Darkness 
changes that rule. All objects not directly carried by the player become 
out of scope.

One of the advantages of an advanced design system like Inform is the 
flexibility to change all default behaviours to suit your particular 
needs. Scope problems are no different. There is a set of routines and 
functions to tamper with what's in scope when. We'll see just a tiny 
example to fix our particular problem. In the section "``Entry point 
routines``" of our game -- after the ``Initialise`` routine, for 
instance -- include the following lines:

.. code-block:: inform

  [ InScope person;
      if (person == player && location == thedark && real_location == toilet) {
          PlaceInScope(light_switch);
          PlaceInScope(toilet_door);
      }
      return false;
  ];

:samp:`InScope({actor_obj_id})` is an entry point routine that can tamper
with the scope rules for the given :samp:`{actor_obj_id}` (either the
player character or a NPC). We define it with one variable (which we name
as we please; it's also a good idea to name variables in an intuitive way
to remind us of what they represent), ``person`` , and then we make a
complex test to see if the player is actually in the toilet and in the
dark.

We have told you that the library variable :var:`location` holds the 
current 
room that the player is in. However, when there is no light, the 
variable location gets assigned to the value of the special library 
object thedark . It doesn't matter if we have ten dark rooms in our 
game; location will be equal to thedark in all of them. There is yet 
another variable, called :var:`real_location`, which holds the room the 
player is in *even when there is no light to see by*.

So the test:

.. code-block:: inform

  if (person == player && location == thedark && real_location == toilet) ...

is stating: if the specified actor is the :var:`player` character *and* he 
finds himself in the dark *and* he actually happens to be in the 
toilet...

Then we make a call to one of the library routines,
:samp:`PlaceInScope({obj_id})`, which has a very descriptive name: it
places in scope the given object. In our case, we want both the door and
the light switch to be within reach of the player, hence both additional
lines. Finally, we must ``return false``, because we want the normal scope
rules for the defined actor -- the player -- to apply to the rest of the
objects of the game (if we returned :const:`true`, players would find that they
are able to interact with very little indeed). Now we get a friendlier and
more logical response:

.. code-block:: transcript

  Darkness
  It is pitch dark, and you can't see a thing.

  >TURN ON SWITCH
  You turn on the light in the toilet.

  Unisex toilet
  A surprisingly CLEAN square room covered with glazed-ceramic tiles, featuring
  little more than a lavatory and a light switch. The only exit is south, through
  the door and into the cafe.

And the same would happen with the door. Notice how the room description 
gets displayed after we pass from dark to light; this is the normal 
library behaviour.

There is still one final problem which, admittedly, might originate from 
an improbable course of action; however, it could be a nuisance. Suppose 
that the player enters the toilet, locks the door -- which is possible 
in the dark now that the door is in scope -- and then drops the key. 
There's no way to exit the toilet -- because the door is locked and the 
key has disappeared, engulfed by the darkness -- unless the player 
thinks to turn on the light switch, thereby placing the key in scope 
once more.

Why don't we add a :samp:`PlaceInScope({toilet_key})` to the above routine?
Well, for starters, the key can be moved around (as opposed to the door or
the light switch, which are fixed items in the toilet room). Suppose the
player opens the door of the toilet, but drops the key in the café, then
enters the toilet and closes the door. The condition is met and the key is
placed in scope, when it's in another room. Second, this is a simple game
with just a few objects, so you can define a rule for each of them; but in
any large game, you might like to be able to refer to objects in bunches,
and make general rules that apply to all (or some) of them.

We need to add code to the ``InScope`` routine, telling the game to 
place in scope all objects that we drop in the dark, so that we might 
recover them (maybe going on all fours and groping a little, but it’s a 
possible action). We don’t want the player to have other objects in 
scope (like the coin, for instance), so it might be good to have a way 
of testing if the objects have been touched and carried by the player. 
The attribute :attr:`moved` is perfect for this. The library sets it for 
every object that the player has picked up at one time in the game; 
:attr:`scenery` and :attr:`static` objects, and those we have not yet seen don't 
have :attr:`moved`. Here is the reworked ``InScope`` routine. There are a 
couple of new concepts to look at:

.. code-block:: inform

  [ InScope person item;
      if (person == player && location == thedark && real_location == toilet) {
          PlaceInScope(light_switch);
          PlaceInScope(toilet_door);
      }
      if (person == player && location == thedark)
          objectloop (item in parent(player))
              if (item has moved) PlaceInScope(item);
      return false;
  ];

We have added one more local variable to the routine, ``item`` -- again, 
this is a variable we have created and named on our own; it is not part 
of the library. We make now a new test: if the actor is the player and 
the location is any dark room, then perform a certain action. We don't 
need to specify the toilet, because we want this rule to apply to all 
dark rooms (well, the only dark room in the game *is* the toilet, but we 
are trying to provide a general rule).

   :samp:`objectloop (variable) {statement};`

is a loop statement, one of the four defined in Inform. A loop statement is
a construct that allows you to run several times through a statement (or a
statement block). ``objectloop`` performs the :samp:`{statement}` once for
every object defined in the (:samp:`{variable}`) . If we were to code:

   :samp:`objectloop (item) {statement};`

then the :samp:`{statement}` would be executed once for each object in the
game. However, we want to perform the statement only for those objects
whose parent object is the same as the player's parent object: that is, for
objects in the same room as the player, so we instead code:

   :samp:`objectloop (item in parent(player)) {statement};`

What is the actual :samp:`{statement}` that we'll repeatedly execute?

.. code-block:: inform

  if (item has moved)
      PlaceInScope(item);

The test: ``if (item has moved)`` ensures that ``PlaceInScope(item)`` 
deals only with objects with the :attr:`moved` attribute set. So: if the 
player is in the dark, let’s go through the objects which are in the 
same room, one at a time. For each of them, check if it's an item that 
the player has at some time carried, in which case, place it in scope. 
All dropped objects within the room were carried at one time, so we let 
players recollect them even if they can’t see them.

As you see, darkness has its delicate side. If you plan to have dark 
rooms galore in your games, bear in mind that you are in for some 
elaborate code (unless you let the library carry on with default rules, 
in which case there won't be much for your players to do).


Amazing techicolour dreamcoats
==============================

This leaves us the clothing items themselves, which will require a few 
tailored actions. Let's see first the ordinary garments of John Covarth:

.. code-block:: inform

  Object  clothes "your clothes"
    with  name 'ordinary' 'street' 'clothes' 'clothing',
          description
              "Perfectly ORDINARY-LOOKING street clothes for a NOBODY like
               John Covarth.",
          before [;
            Wear:
              if (self has worn)
                  "You are already dressed as John Covarth.";
              else
                  "The town NEEDS the power of Captain FATE, not the anonymity
                   of John Covarth.";
            Change,Disrobe:
              if (self hasnt worn)
                 "Your KEEN eye detects that you're no longer wearing them.";
              switch (location) {
                street:
                  if (player in booth)
                      "Lacking Superman's super-speed, you realise that it
                       would be awkward to change in plain view of the passing
                       pedestrians.";          
                  else
                      "In the middle of the street? That would be a PUBLIC
                       SCANDAL, to say nothing of revealing your secret
                       identity.";
                cafe:
                      "Benny allows no monkey business in his establishment.";
                toilet:
                  if (toilet_door has open)
                      "The door to the bar stands OPEN at tens of curious eyes.
                       You'd be forced to arrest yourself for LEWD conduct.";
                  print "You quickly remove your street clothes and bundle them
                         up together into an INFRA MINUSCULE pack ready for easy
                         transportation. ";
                  if (toilet_door has locked) {
                      give clothes ~worn; give costume worn;
                      "Then you unfold your INVULNERABLE-COTTON costume and
                       turn into Captain FATE, defender of free will, adversary
                       of tyranny!";
                  }
                  else {
                      deadflag = 3;
                      "Just as you are slipping into Captain FATE's costume,
                       the door opens and a young woman enters. She looks at
                       you and starts screaming, ~RAPIST! NAKED RAPIST IN THE
                       TOILET!!!~^^
                       Everybody in the cafe quickly comes to the rescue, only
                       to find you ridiculously jumping on one leg while trying
                       to get dressed. Their laughter brings a QUICK END to
                       your crime-fighting career!";
                  }
                thedark:
                  "Last time you changed in the dark, you wore the suit inside
                   out!";
                default:                  ! this _should_ never happen...
                  "There must be better places to change your clothes!";
              }
          ],
    clothing proper pluralname;

See how the object deals only with ``Wear``, ``Disrobe`` and ``Change``. 
``Wear`` and ``Disrobe`` are standard library actions already defined in 
Inform, but we'll have to make a new verb to allow for CHANGE CLOTHES. 
In this game, ``Disrobe`` and ``Change`` are considered synonymous for 
all purposes; we'll deal with them first.

The goal of the game is for players to change their clothes, so we might 
expect them to try this almost anywhere; but first of all we have to 
check that the ``clothes`` object is actually being worn. If not, we 
display a message reminding the player that this action has become 
irrelevant. What we do with the ``switch`` statement is to offer a 
variety of responses according to the :var:`location` variable. The street 
(in or out of the booth) and the café all display refusals of some kind, 
until the player character manages to enter the toilet, where we 
additionally require that he locks the door before taking off his 
clothes. If the door is closed but not locked, he is interrupted in his 
naked state by a nervous woman who starts shouting, and the game is lost 
(this is not as unfair as it seems, because the player may always revert 
to the previous state with UNDO). If the door is locked, he succeeds in 
his transformation (we take away the :attr:`worn` attribute from the 
``clothes`` and give it to the ``costume`` instead). We add a special 
refusal to change in the dark, forcing players to turn on the light and 
then, we hope, to find the coin. And finally we code a ``default`` 
entry; you'll remember that, in a ``switch`` statement, this is supposed 
to cater for any value not explicitly listed for the expression under 
control -- in this case, for the variable :var:`location`. Since we have 
already gone through all the possible locations of the game, this entry 
appears only as a defensive measure, just in case something unexpected 
happens (for instance, we might extend the game with another room and 
forget about this ``switch`` statement). In normal and controlled 
conditions, it should never be reached, but it doesn't hurt one bit to 
have it there.

The ``Wear`` action just checks if these clothes are already being worn, 
to offer two different rejection responses: the goal of the game is to 
change into the hero's suit, after which we'll prevent a change back 
into ordinary clothes. So now we are dealing with a Captain Fate in full 
costume:

.. code-block:: inform

  Object   costume "your costume"
    with   name 'captain' 'captain^s' 'fate' 'fate^s' 'costume' 'suit',
           description
               "STATE OF THE ART manufacture, from chemically reinforced 100%
                COTTON-lastic(tm).",
           before [;
             Wear:
               if (self has worn)
                   "You are already dressed as Captain FATE.";
               else
                   "First you'd have to take off your commonplace unassuming
                    John Covarth INCOGNITO street clothes.";
             Change,Disrobe:
               if (self has worn)
                   "You need to wear your costume to FIGHT crime!";
               else
                   "But you're not yet wearing it!";
             Drop:
               "Your UNIQUE Captain FATE multi-coloured costume? The most
                coveted clothing ITEM in the whole city? Certainly NOT!";
           ],
    has    clothing proper;

Note that we intercept the action WEAR COSTUME and hint that players 
should try TAKE OFF CLOTHES instead. We don't let them take off the 
costume once it’s being worn, and we certainly don't let them misplace 
it anywhere, by refusing to accept a ``Drop`` action.


It's a wrap
===========

Nearly there; just a few minor odds and ends to round things off.

.. rubric:: Initialise routine

All the objects of our game are defined. Now we must add a couple of 
lines to the ``Initialise`` routine to make sure that the player does 
not start the game naked:

.. code-block:: inform

  [ Initialise;
      #Ifdef DEBUG; pname_verify(); #Endif;       ! suggested by pname.h
      location = street;
      move costume to player;
      move clothes to play; give clothes worn;
      lookmode = 2;
      "^^Impersonating mild mannered John Covarth, assistant help boy at an
       insignificant drugstore, you suddenly STOP when your acute hearing
       deciphers a stray radio call from the POLICE. There's some MADMAN
       attacking the population in Granary Park! You must change into your
       Captain FATE costume fast...!^^";
  ];

Remember that we included a disambiguation package, ``pname.h``? There 
were some additional comments in the accompanying text file that should 
be taken in consideration:

  pname.h provides a pname_verify routine. When DEBUG is defined, you 
  may call pname_verify() in your Initialise() routine to verify the pname 
  properties in your objects.

The designer of the package has made a debugging tool (a routine) to 
check for errors when using his library, and he tells us how to use it. 
So we include the suggested lines into our ``Initialise`` routine:

.. code-block:: inform

  #Ifdef DEBUG; pname_verify(); #Endif;

As the text explains, what this does is: first check whether the game is 
being compiled in Debug mode; if this is the case, run the 
``pname_verify`` routine, so that it tests all ``pname`` properties to 
see if they are written correctly.

.. rubric:: Demise of our hero

We have made three possible endings:

#.  The player attempts to change in the toilet with an unlocked door.

#.  The player tries to attack Benny while wearing the costume.

#.  The player manages to exit the café dressed as Captain Fate.

(1) and (2) lose the game, (3) wins it. The library defaults for these 
two states display, respectively,

.. code-block:: transcript

  *** You have died ***

  *** You have won ***

These states correspond to the values of the :var:`deadflag` variable: 1 
for losing, 2 for winning. However, we have made up different messages, 
because our hero does not really die -- ours suffers a FATE worse than 
death -- and because we want to give him a more descriptive winning 
line. Therefore, we must define a ``DeathMessage`` routine as we did in 
"William Tell", to write our customised messages and assign them to 
:var:`deadflag` values greater than 2.

.. code-block:: inform

  [ DeathMessage;
      if (deadflag == 3) print "Your secret identity has been revealed";
      if (deadflag == 4) print "You have been SHAMEFULLY defeated";
      if (deadflag == 5) print "You fly away to SAVE the DAY";
  ];

.. rubric:: Grammar

Finally, we need to extend the existing grammar, to allow for a couple 
of things. We have already seen that we need a verb CHANGE. We'll make 
it really simple:

.. code-block:: inform

  [ ChangeSub;
      if (noun has pluralname) print "They're";
      else                     print "That's";
      " not something you must change to save the day.";
  ];

  Verb 'change' 'exchange' 'swap' 'swop'
      * noun                     -> Change;

Just notice how the verb handler checks whether the noun given is plural 
or singular, to display a suitable pronoun.

A further detail: when players are in the café, they might ask Benny for 
the coffee (as we intend and heavily hint), for a sandwich or a pastry 
(both mentioned in the café description), for food or a snack (mentioned 
here and there, and we have provided for those); but what if they try a 
meat pie? Or scrambled eggs? There’s just so much decoration one can 
reasonably insert in a game, and loading the dictionary with Benny’s 
full menu would be overdoing it a bit.

One might reasonably imagine that the ``default`` line at the end of the 
``Give`` action in the orders property handles every input not already 
specified:

.. code-block:: inform

  orders [;
    Give:
      switch (noun) {
        toilet_key:  ! code for the key...
        coffee:      ! code for the coffee...
        food:        ! code for the food...
        menu:        ! code for the menu...
        default:
          "~I don't think that's on the menu, sir.~";
      }
  ],

Not so. The library grammar that deals with ASK BENNY FOR... is this
(specifically, the last line):

.. code-block:: inform

  Verb 'ask'
      * creature 'about' topic    -> Ask
      * creature 'for' noun       -> AskFor

You'll see the :var:`noun` token, which means that whatever the player asks 
him for must be a real game object, visible at that moment. Assuming 
that the player mentions such an object, the interpreter finds it in the 
dictionary and places its internal ID in the :var:`noun` variable, where 
our ``switch`` statement can handle it. So, ASK BENNY FOR KEY assigns 
the ``toilet_key`` object to the noun variable, and Benny responds. ASK 
BENNY FOR CUSTOMERS also works; the ``default`` case picks that one up. 
But, ASK BENNY FOR SPAGHETTI BOLOGNESE won't work: we have no object for 
Spaghetti Bolognese (or any other delicacy from Benny's kitchen) -- the 
words ``'spaghetti'`` and ``'bolognese'`` simply aren't in the 
dictionary. This is perhaps not a major deficiency in our game, but it 
takes very little to allow Benny to use his default line for *any* 
undefined input from the player. We need to extend the existing ASK 
grammar:

.. code-block:: inform

  Extend 'ask'
      * creature 'for' topic    -> AskFor;

This line will be added to the end of the existing grammar for Ask, so 
it doesn’t override the conventional noun-matching line. ``topic`` is a 
token that roughly means “any input at all”; the value of noun isn't 
important, because it'll be handled by the default case. Now players may 
ask Benny for a tuna sandwich or a good time; they'll get: "I don’t 
think that’s on the menu, sir", which makes Benny a barman with 
attitude.

And that's it; on the slightly surreal note of ASK BENNY FOR A GOOD TIME 
we've taken "Captain Fate" as far as we intend to. The guide is nearly 
done. All that's left is to recap some of the more important issues, 
talk a little more about compilation and debugging, and send you off 
into the big wide world of IF authorship.


.. rubric:: Footnotes

.. [#dark]

  We're alluding here to the Classical concept of mimesis. In an 
  oft-quoted essay from 1996, Roger Giner-Sorolla wrote: "I see 
  successful fiction as an imitation or 'mimesis' of reality, be it 
  this world's or an alternate world's. Well-written fiction leads the 
  reader to temporarily enter and believe in the reality of that world. 
  A crime against mimesis is any aspect of an IF game that breaks the 
  coherence of its fictional world as a representation of reality."