X-Git-Url: https://jxself.org/git/?p=ibg.git;a=blobdiff_plain;f=chapters%2F12.rst;h=0260f67233a9f16e37de7eb10843fdd3d762af46;hp=595c0b160aeae1a7212c943de2f1f7fdbbf77441;hb=fb8b7c14f10733e913e2b87f9a82e5b44c0dc7be;hpb=6ca42969f45428daf7299356ac622a4640b078f9 diff --git a/chapters/12.rst b/chapters/12.rst index 595c0b1..0260f67 100644 --- a/chapters/12.rst +++ b/chapters/12.rst @@ -4,27 +4,26 @@ Captain Fate: take 3 .. epigraph:: - | *W was a watchman, and guarded the door;* - | *X was expensive, and so became poor.* + | |CENTER| *W was a watchman, and guarded the door;* + | |CENTER| *X was expensive, and so became poor.* .. only:: html .. image:: /images/picW.png :align: left -.. raw:: latex - - \dropcap{w} - -e've given ourselves an interesting challenge by overusing that -convenient word "toilet", and here we show you how we resolve the -ambiguities that have been introduced. Also, it's time for the eponymous +|W|\e've given ourselves an interesting challenge by overusing that +convenient word "toilet", and here we show you how we resolve the +ambiguities that have been introduced. Also, it's time for the eponymous owner of Benny's café to be developed in full. Too many toilets ================ -If you check the ``name`` properties of the toilet door, the toilet key +.. index:: + single: ambiguous objects + +If you check the :prop:`name` properties of the toilet door, the toilet key and the toilet room, you’ll see that the dictionary word ``'toilet'`` occurs in all of them. There won't be any problems if players mention the words DOOR or KEY, but we reach a strange impasse should they try to @@ -52,7 +51,7 @@ could benefit from the effort. The product of this generosity takes the form of a library extension: the solution neatly packaged as a file that other designers can incorporate into their source code. These files can be found in the IF Archive: go to -``http://mirror.ifarchive.org/indexes/if-archive.html`` and then select +http://mirror.ifarchive.org/indexes/if-archive.html and then select "``.../infocom``", "``.../compilers``", "``.../inform6``", "``.../library``", and "``.../contributions``". All of these files contain Inform code. To use a library extension (also known as a library @@ -64,15 +63,14 @@ there are rules about where exactly this Include should be placed in your source code. It is not unusual to find other suggestions and warnings. -To help us out of the disambiguation problem with the word TOILET, we -are going to use Neil Cerutti's extension ``pname.h``, which is designed -for situations precisely like this. First, we follow the link to the IF -archive and download the compressed file ``pname.zip``, which contains -two more files: ``pname.h`` and ``pname.txt``. We place these files in -the folder where we are currently developing our game or, if using the -environment we proposed in "Tools of the trade" on page 17, in the -``Inform\Lib\Contrib`` folder. The text file offers instructions about -installation and usage. Here we find a warning: +To help us out of the disambiguation problem with the word TOILET, we are +going to use Neil Cerutti's extension ``pname.h``, which is designed for +situations precisely like this. First, we follow the link to the IF archive +and download the compressed file ``pname.zip``, which contains two more +files: ``pname.h`` and ``pname.txt``. We place these files in the folder +where we are currently developing our game or, if using the environment we +proposed in :doc:`02`, in the ``Inform\Lib\Contrib`` folder. The text file +offers instructions about installation and usage. Here we find a warning: This version of pname.h is recommended for use only with version 6/10 of the Inform Library. @@ -83,21 +81,21 @@ some routines at the heart of the standard library; these may not be identical in other Inform versions. The introduction explains what ``pname.h`` does for you; namely, it lets -you avoid using complicated ``parse_name`` routines to disambiguate the +you avoid using complicated :prop:`parse_name` routines to disambiguate the player's input when the same dictionary word refers to more than one -item. A ``parse_name`` routine would have been the solution to our +item. A :prop:`parse_name` routine would have been the solution to our problem before the existence of this file, and it qualifies as an advanced programming topic, difficult to master on a first approach. Fortunately, we don't need to worry. Neil Cerutti explains: The ``pname.h`` package defines a new object property, ``pname`` (short for phrase name), with a similar look and feel to the standard - ``name`` property: both contain a list of dictionary words. However, + :prop:`name` property: both contain a list of dictionary words. However, in a ``pname`` property the order of the words is significant, and special operators ``'.p'`` ``'.or'`` and ``'.x'`` enable you to embed some intelligence into the list. In most cases where the standard - ``name`` property isn't enough, you can now just replace it with a - ``pname`` property, rather than write a ``parse_name`` property + :prop:`name` property isn't enough, you can now just replace it with a + ``pname`` property, rather than write a :prop:`parse_name` property routine. We'll soon see how it works. Let's take a look at the installation @@ -108,14 +106,19 @@ instructions: #. Add four lines near the head of the program (before you include ``Parser.h``). - ``Replace MakeMatch;`` - ``Replace Identical;`` - ``Replace NounDomain;`` - ``Replace TryGivenObject;`` + .. code-block:: inform + + Replace MakeMatch; + Replace Identical; + Replace NounDomain; + Replace TryGivenObject; #. Include the ``pname.h`` header just after you include ``Parser.h``. - ``Include "Parser";`` - ``Include "pname";`` + + .. code-block:: inform + + Include "Parser"; + Include "pname"; #. Add ``pname`` properties to those objects which require phrase recognition. @@ -125,7 +128,7 @@ It seems simple enough. So, following steps one and two, we add those ``pname.h`` right after it. ``Replace`` tells the compiler that we're providing replacements for some standard routines. -.. code-block:: inform6 +.. code-block:: inform Constant Story "Captain Fate"; Constant Headline @@ -142,39 +145,35 @@ providing replacements for some standard routines. Include "Parser"; Include "pname"; - !... + ... Now our source code is ready to benefit from the library package. How does it work? We have acquired a new property -- ``pname`` -- which can be added to some of our objects, and which works pretty much like a -``name`` property. In fact, it should be used *instead* of a ``name`` +:prop:`name` property. In fact, it should be used *instead* of a :prop:`name` property where we have a disambiguation problem. Let’s change the relevant lines for the toilet door and the toilet key: -.. todo:: - - Maybe specially highlight the lines using pname? - -.. code-block:: inform6 +.. code-block:: inform Object toilet_door with pname '.x' 'red' '.x' 'toilet' 'door', short_name [; - !... + ... Object toilet_key "toilet key" benny with pname '.x' 'toilet' 'key', article "the", - !... + ... while leaving the ``outside_of_toilet`` unchanged: -.. code-block:: inform6 +.. code-block:: inform Object outside_of_toilet "toilet" cafe with name 'toilet' 'bath' 'rest' 'room' 'bathroom' 'restroom', before [; - !... + ... We are now using a new operator -- ``'.x'`` -- in our ``pname`` word lists. explains @@ -186,7 +185,7 @@ and this makes the dictionary word ``'toilet'`` of lesser importance for these objects, so that at run-time players could refer to the DOOR or TOILET DOOR or the KEY or TOILET KEY -- but not simply to the TOILET -- when referring to either the door or the key. And, by leaving unchanged -the name property of the outside_of_toilet object – where there is also +the name property of the ``outside_of_toilet`` object – where there is also another ``'toilet'`` entry -- the ``pname`` properties will tell the interpreter to discard the key and the door as possible objects to be considered when players refer just to TOILET. Looking at it in terms of @@ -223,7 +222,7 @@ a coin near the lavatory, enough cash to pay for the coffee. And that about sums it all up; pretty simple to describe -- not so simple to code. Remember Benny's basic definition from the previous chapter: -.. code-block:: inform6 +.. code-block:: inform Object benny "Benny" cafe with name 'benny', @@ -233,10 +232,10 @@ code. Remember Benny's basic definition from the previous chapter: strikes him.", has scenery animate male proper transparent; -We can now add some complexity, beginning with a ``life`` property. In +We can now add some complexity, beginning with a :prop:`life` property. In generic form: -.. code-block:: inform6 +.. code-block:: inform life [; Give: !... code for giving objects to Benny @@ -248,6 +247,8 @@ generic form: We have seen some of these actions before. We'll take care of the easier ones: +.. code-block:: inform + Attack: if (costume has worn) { deadflag = 4; @@ -284,7 +285,7 @@ the coffee has been paid for, and whether the toilet key has been returned. The solution, yet again (this really is a most useful capability), is more local property variables: -.. code-block:: inform6 +.. code-block:: inform Object benny "Benny" cafe with name 'benny', @@ -296,14 +297,14 @@ capability), is more local property variables: coffee_not_paid false, ! is Benny waiting to be paid? key_not_returned false, ! is Benny waiting for the key? live [; - !... + ... -Now we are ready to tackle the ``Give`` action of the ``life`` property, +Now we are ready to tackle the ``Give`` action of the :prop:`life` property, which deals with commands like GIVE THE KEY TO BENNY (in a moment, we'll -come to the ``Give`` action of the ``orders`` property, which deals with +come to the ``Give`` action of the :prop:`orders` property, which deals with commands like BENNY, GIVE ME THE KEY): -.. code-block:: inform6 +.. code-block:: inform Give: switch (noun) { @@ -328,35 +329,34 @@ commands like BENNY, GIVE ME THE KEY): back anytime,~ he says."; } -The Give action in the ``life`` property holds the variable ``noun`` as +The Give action in the :prop:`life` property holds the variable :var:`noun` as the object offered to the NPC. Remember that we can use the ``switch`` statement as shorthand for: -.. code-block:: inform6 +.. code-block:: inform if (noun == costume) { whatever }; if (noun == clothes) { whatever }; - !... - -We won't let players give away their clothes or their costume (yes, an -improbable action, but you never know). The toilet key and the coin are -successfully transferred. The property ``key_not_returned`` will be set -to true when we receive the toilet key from Benny (we have not coded -that bit yet), and now, when we give it back, it's reset to ``false``. -The ``move`` statement is in charge of the actual transfer of the object -from the player's inventory to Benny, and we finally display a -confirmation message. With the coin, we find a new statement: -``remove``. This extracts the object from the object tree, so that it -now has no parent. The effect is to make it disappear from the game -(though you are not destroying the object permanently -- and indeed you -could return it to the object tree using the ``move`` statement); as far -as the player is concerned, there isn’t a COIN to be found anywhere. The -``coffee_not_paid`` property will be set to true when Benny serves us -the cup of coffee (again, we’ll see that in a moment); now we reset it -to ``false``, which liberates the player from debt. This culminates with -the ``"..."`` print-and-return statement, telling the player that the -action was successful. In passing, remember that in "A homely -atmosphere" on page 131 we defined the counter such that PUT KEY ON + ... + +We won't let players give away their clothes or their costume (yes, an +improbable action, but you never know). The toilet key and the coin are +successfully transferred. The property ``key_not_returned`` will be set to +true when we receive the toilet key from Benny (we have not coded that bit +yet), and now, when we give it back, it's reset to :const:`false`. The ``move`` +statement is in charge of the actual transfer of the object from the +player's inventory to Benny, and we finally display a confirmation +message. With the coin, we find a new statement: ``remove``. This extracts +the object from the object tree, so that it now has no parent. The effect +is to make it disappear from the game (though you are not destroying the +object permanently -- and indeed you could return it to the object tree +using the ``move`` statement); as far as the player is concerned, there +isn’t a COIN to be found anywhere. The ``coffee_not_paid`` property will be +set to true when Benny serves us the cup of coffee (again, we’ll see that +in a moment); now we reset it to :const:`false`, which liberates the player from +debt. This culminates with the ``"..."`` print-and-return statement, +telling the player that the action was successful. In passing, remember +that in :ref:`homely-atmos` we defined the counter such that PUT KEY ON COUNTER is automatically translated into GIVE KEY TO BENNY . Why move the key to Benny but remove the coin instead? Once players @@ -369,13 +369,13 @@ indulge in caffeine. Once the coin is paid, it disappears for good, supposedly into Benny's greedy pockets. No need to worry about it any more. -The benny object needs also an ``orders`` property, just to take care of +The benny object needs also an :prop:`orders` property, just to take care of the player's requests for coffee and the key, and to fend off any other -demands. The ``Give`` action in an ``orders`` property deals with inputs +demands. The ``Give`` action in an :prop:`orders` property deals with inputs like ASK BENNY FOR THE KEY or BENNY, GIVE ME THE KEY. The syntax is -similar to that of the ``life`` property: +similar to that of the :prop:`life` property: -.. code-block:: inform6 +.. code-block:: inform orders [; ! handles ASK BENNY FOR X and BENNY, GIVE ME XXX Give: @@ -415,7 +415,7 @@ similar to that of the ``life`` property: } ], -* We test the value of ``second`` in order to trap over-generous +* We test the value of :var:`second` in order to trap over-generous gestures such as BENNY, GIVE COFFEE TO CUSTOMERS . Then we consider potential requests. @@ -428,9 +428,9 @@ similar to that of the ``life`` property: possessions -- a perverse player could get the key, then drop it somewhere and ask for it again; if this should happen, we indicate that Benny is nobody's fool with the message ``"~Last place I saw - that key..."``. Once all these fitting conditions are ``true``, + that key..."``. Once all these fitting conditions are :const:`true`, players will get the key, which means that they have to return it -- - the ``key_not_returned`` property becomes ``true`` -- and we display + the ``key_not_returned`` property becomes :const:`true` -- and we display a suitable message. However, if the player didn't ask for a coffee, Benny refuses to oblige, mentioning for the first time the menu board where players will be able to see a picture of a cup of coffee when @@ -440,9 +440,9 @@ similar to that of the ``life`` property: * **Coffee:** we check whether players have already asked for a coffee, by testing the ``coffee_asked_for`` property, and refuse to serve - another one if ``true``. If ``false``, we place the coffee on the + another one if :const:`true`. If :const:`false`, we place the coffee on the counter, and set the properties ``coffee_asked_for`` and - ``coffee_not_paid`` to ``true``. The message bit you know about. + ``coffee_not_paid`` to :const:`true`. The message bit you know about. * **Food:** we'll provide an object to deal with all of the delicious comestibles to be found in the café, specifically those (such as @@ -466,7 +466,7 @@ indeed he will. But where? We must revisit the café room object: -.. code-block:: inform6 +.. code-block:: inform Room cafe "Inside Benny's cafe" with description @@ -523,19 +523,19 @@ description: we could have assigned a new value to the ``player.description`` variable, but opted to use the ``LibraryMessages`` object instead. This is a similar case. The code causing Benny to intercept the forgetful player could have been added, -perhaps, to a ``daemon`` property in Benny’s definition. However, since +perhaps, to a :prop:`daemon` property in Benny’s definition. However, since the action to be intercepted is always the same one and happens to be a movement action when the player tries to leave the café room, it is also possible to code it by trapping the ``Go`` action of the room object. Both would have been right, but this is somewhat simpler. -We have added a ``before`` property to the room object (albeit a longish +We have added a :prop:`before` property to the room object (albeit a longish one), just dealing with the ``Go`` action. As we mentioned in an earlier chapter, this technique lets you trap the player who is about to exit a room before the movement actually takes place, a good moment to interfere if we want to prevent escape. The first line: -.. code-block:: inform6 +.. code-block:: inform if (noun ~= s_obj) return false; @@ -557,14 +557,14 @@ attempt to leave: The first three are covered by the test: -.. code-block:: inform6 +.. code-block:: inform if (benny.coffee_not_paid == true || benny.key_not_returned == true) ... that is, if either the coffee is not paid for *or* if the key is not -returned. When this condition is ``false``, it means that both +returned. When this condition is :const:`false`, it means that both misdemeanours have been avoided and that the player is free to go. -However, when this condition is ``true``, the hand of Benny falls on the +However, when this condition is :const:`true`, the hand of Benny falls on the player's shoulder and then the game displays a different message according to which fault or faults the player has committed.