| *E was an esquire, with pride on his brow;*
| *F was a farmer, and followed the plough.*
-Each of the three games in this guide is created step by step; you'll get
+.. only:: html
+
+ .. image:: /images/picE.png
+ :align: left
+
+.. raw:: latex
+
+ \dropcap{e}
+
+ach of the three games in this guide is created step by step; you'll get
most benefit (especially to begin with) if you take an active part, typing
in the source code on your computer. Our first game, described in this
chapter and the two which follow, tells this sentimental little story:
Ensure the file is named ``Heidi.inf``, rather than ``Heidi.txt`` or
``Heidi.inf.txt``.
- Remember that, throughout this guide, we place the "TYPE" symbol
+ Remember that, throughout this guide, we place the "``TYPE``" symbol
alongside pieces of code that we recommend you to type into your own
game files as you read through the examples (which, conversely, means
- that you don't need to type the unmarked pieces of code). You'll learn
- Inform more quickly by trying it for yourself, rather than just taking
- our word for how things work.
+ that you *don't* need to type the unmarked pieces of code). You'll
+ learn Inform more quickly by trying it for yourself, rather than just
+ taking our word for how things work.
.. todo::
source. The instructions most commonly placed here are compiler
switches, a way of controlling detailed aspects of how the compiler
operates. These particular switches, two of many, are turning on
- **Strict mode**, which makes the game less likely to misbehave when being
- played, and **Debug mode**, which provides some extra commands which can
- be helpful when tracking down problems.
+ :term:`Strict mode`, which makes the game less likely to misbehave when
+ being played, and :term:`Debug mode`, which provides some extra commands
+ which can be helpful when tracking down problems.
.. note::
line is ignored; if the ``!`` is halfway along a line, the compiler takes
note of the first half, and then ignores the exclamation mark and
everything after it on that line. We call material following an
- exclamation mark, not seen by anybody else, a **comment**; it's often a
- remark that we write to remind ourselves of how something works or why we
- tackled a problem in a particular way. There's nothing special about
+ exclamation mark, not seen by anybody else, a :term:`comment`; it's often
+ a remark that we write to remind ourselves of how something works or why
+ we tackled a problem in a particular way. There's nothing special about
those equals signs: they just produce clear lines across the page.
It's always a good idea to comment code as you write it, for later it
By the way, the compiler *doesn't* give special treatment to exclamation
marks in quoted text: ``!`` within quotes "..." is treated as a normal
character. On this line, the first ``!`` is part of the sequence (or
- string) of characters to be displayed:
+ :term:`string`) of characters to be displayed:
.. code-block:: inform
you've typed, so it's worthwhile taking a bit of care to make it as
readable as possible.
-* Every game should have the **constant** definitions for ``Story`` (the
- game's name) and ``Headline`` (typically, information on the game's
- theme, copyright, authorship and so on). These two **string** values,
- along with a release number and date, and details of the compiler,
- compose the **banner** which is displayed at the start of each game.
+* Every game should have the :term:`constant` definitions for ``Story``
+ (the game's name) and ``Headline`` (typically, information on the game's
+ theme, copyright, authorship and so on). These two :term:`string`
+ values, along with a release number and date, and details of the
+ compiler, compose the :term:`banner` which is displayed at the start of
+ each game.
* Every game needs the three lines which ``Include`` the standard library
files -- that is, they merge those files' contents into your source file:
Include "Parser";
Include "VerbLib";
- ! ...
+ ...
Include "Grammar";
They always have to be in this order, with ``Parser`` and ``VerbLib``
[ Initialise; ];
- The **routine** that we've defined here doesn't do anything useful, but
- it still needs to be present. Later, we'll come back to ``Initialise``
- and explain what a routine is and why we need this one.
+ The :term:`routine` that we've defined here doesn't do anything useful,
+ but it still needs to be present. Later, we'll come back to
+ ``Initialise`` and explain what a routine is and why we need this one.
* You'll notice that each of the items mentioned in the previous three
rules ends with a semicolon. Inform is very fussy about its punctuation,
.. image:: /images/heidi1.*
:align: center
-In IF, we talk about each of these locations as a **room**, even though in
-this example none of them has four walls. So let's use Inform to define
+In IF, we talk about each of these locations as a :term:`room`, even though
+in this example none of them has four walls. So let's use Inform to define
those rooms. Here's a first attempt:
.. code-block:: inform
commonly, that light source is the room itself.
A smidgeon of background may help set this into context (there's more in
-the next chapter). An object can have both **properties** (introduced by
-the keyword ``with``) and **attributes** (written after the word ``has``).
-A property has both a name (like ``description``) and a value (like the
-character string "``You stand outside a cottage. The forest stretches
-east.``"); an attribute has merely a name.
+the next chapter). An object can have both :term:`properties` (introduced
+by the keyword ``with``) and :term:`attributes` (written after the word
+``has``). A property has both a name (like ``description``) and a value
+(like the character string "``You stand outside a cottage. The forest
+stretches east.``"); an attribute has merely a name.
In a little while, when you play this game, you'll observe that it starts
like this:
[ Initialise; location = before_cottage; ];
-``location`` is a **variable**, part of the library, which tells the
+``location`` is a :term:`variable`, part of the library, which tells the
interpreter in which room the player character currently is. Here, we're
saying that, at the start of the game, the player character is in the
``before_cottage`` room.
has ;
The ``name`` introduces a list in single quotes '...'. We call each of
-those quoted things a **dictionary word**, and we do mean "word", not
+those quoted things a :term:`dictionary word`, and we do mean "word", not
"phrase" (``'baby'``\ ``'bird'`` rather than ``'baby bird'``); you can't
-uses spaces, commas or periods in dictionary words, though there's a space
-*between* each one, and the whole list ends with a comma. The idea is that
-the interpreter decides which object a player is talking about by matching
-what she types against the full set of all dictionary words. If the player
-mentions BIRD, or BABY BIRD, or NESTLING, it's the ``baby bird`` that she
-means; if she mentions NEST, BIRD'S NEST or MOSS, it's the ``bird's nest``.
-And if she types NEST BABY or BIRD TWIGS, the interpreter will politely say
-that it doesn't understand what on earth she's talking about.
+uses spaces, commas or periods *in* dictionary words, though there's a
+space *between* each one, and the whole list ends with a comma. The idea
+is that the interpreter decides which object a player is talking about by
+matching what she types against the full set of all dictionary words. If
+the player mentions BIRD, or BABY BIRD, or NESTLING, it's the ``baby bird``
+that she means; if she mentions NEST, BIRD'S NEST or MOSS, it's the
+``bird's nest``. And if she types NEST BABY or BIRD TWIGS, the interpreter
+will politely say that it doesn't understand what on earth she's talking
+about.
.. note::
name 'wide' 'firm' 'flat' 'bough' 'branch',
has static supporter;
-The only new things are those two labels. ``static`` is similar to
-``scenery``: it prevents the branch from being picked up by the player
-character, but *doesn't* suppress mention of it when describing the
-setting. And ``supporter`` is rather like the ``container`` that we used
-for the nest, except that this time the player character can put other
-objects *onto* the branch. (In passing, we'll mention that an object can't
-normally be both a ``container`` and a ``supporter``.) And so here are our
-objects again:
+The only new things are those two labels. ``static`` is similar to
+``scenery``: it prevents the branch from being picked up by the player
+character, but *doesn't* suppress mention of it when describing the
+setting. And ``supporter`` is rather like the ``container`` that we
+used for the nest, except that this time the player character can put
+other objects *onto* the branch. (In passing, we'll mention that an
+object can't normally be both a ``container`` *and* a ``supporter``.)
+And so here are our objects again:
.. code-block:: inform
projects / ibg.git / blobdiff