William Tell: a tale is born
==============================
-.. highlight:: inform6
+.. highlight:: inform
.. epigraph::
- | *K was King William, once governed the land;*
- | *L was a lady, who had a white hand.*
+ | |CENTER| *K was King William, once governed the land;*
+ | |CENTER| *L was a lady, who had a white hand.*
.. only:: html
.. image:: /images/picK.png
:align: left
-.. raw:: latex
-
- \dropcap{k}
-
-eeping up the momentum, this chapter (and the three which follow) works
+|K|\eeping up the momentum, this chapter (and the three which follow) works
steadily through the design of the "William Tell" game that we encountered
right at the start of this guide. Many of the principles are the same as
the ones we explained when designing Heidi and her forest, so we'll not
objects which we haven't yet defined. In any case, we don't intend to
build up the game in layers as we did last time, but rather to talk about
it in logically related chunks. To see (and if you wish, to type) the
-complete source, go to "William Tell" story on page 219.
+complete source, go to :doc:`/appendices/c`.
Object classes
==============
A track heads to the northeast.",
has light;
- ! ...
+ ...
and we explained that just about *every* room needs that ``light``
attribute, or else the player would be literally in the dark. It's a bit
A track heads to the northeast.",
has ;
- ! ...
+ ...
We've done four things:
#. We don't need to explicitly include the ``light`` attribute each time;
every ``Room`` object has it automatically.
-A **class** is a family of closely related objects, all of which behave in
-the same way. Any properties defined for the class, and any attributes
+A :term:`class` is a family of closely related objects, all of which behave
+in the same way. Any properties defined for the class, and any attributes
defined for the class, are automatically given to objects which you specify
as belonging to that class; this process of acquisition just by being a
-member of a class is called **inheritance**. In our example, we've defined
-a ``Room`` class with a ``light`` attribute, and then we've specified four
-objects each of which is a member of that class, and each of which gets
-given a ``light`` attribute as a result of that membership.
+member of a class is called :term:`inheritance`. In our example, we've
+defined a ``Room`` class with a ``light`` attribute, and then we've
+specified four objects each of which is a member of that class, and each of
+which gets given a ``light`` attribute as a result of that membership.
Why have we gone to this trouble? Three main reasons:
"Through the dense foliage, you glimpse a building to the west.
A track heads to the northeast.";
- ! ...
+ ...
You'll notice that, if an object has no block of attributes, the semicolon
which terminates its definition simply moves to the end of its last
property.
-.. rubric:: A class for props
+.. _props-class:
+
+A class for props
+-----------------
We use the ``Room`` class in "William Tell", and a few other classes
besides. Here's a ``Prop`` class (that's "Prop" in the sense of a
nest", ``(a) nest`` would display "a bird's nest", ``(A) nest`` would
display "A bird's nest" and ``(name) nest`` would display just "bird's
nest". This use of a word in parentheses, telling the interpreter how to
- display the following object's internal ID, is called a **print rule**.
+ display the following object's internal ID, is called a :term:`print
+ rule`.
* There's a library variable ``self`` which always contains the internal ID
of the current object, and is really convenient when using a ``Class``.
Prop "south gate" street
with name 'south' 'southern' 'wooden' 'gate',
description "The large wooden gate in the town walls is wide open.",
- ! ...
+ ...
If players type EXAMINE GATE, they'll see "The large wooden gate..."; if
they type CLOSE GATE then the gate's ``before`` property will step in and
increased realism, while clearly hinting to players that trying other verbs
would be a waste of time.
-.. rubric:: A class for furniture
+A class for furniture
+---------------------
The last class for now -- we'll talk about the ``Arrow`` and ``NPC``
classes in the next chapter -- is for furniture-like objects. If you label
Now that most of our class definitions are in place, we can get on with
defining some real rooms and objects. First, though, if you're typing in
the "William Tell" game as you read through the guide, you'd probably like
-to check that what you've entered so far is correct; "Compile-as-you-go" on
-page 233 explains how to compile the game in its current -- incomplete --
-state.
+to check that what you've entered so far is correct;
+:ref:`compile-as-you-go` explains how to compile the game in its current --
+incomplete -- state.
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