15.13. Topic columns

| Chapter 15: Tables |

| 15.13. Topic columns

When double-quoted matter appears in a column of a table, Inform will normally treat that as text for printing out. The exception is when the column is called "topic", where it is treated as text for comparing against what the player has typed. There is really only one operation allowed with topic columns, the "...listed in..." construction, but fortunately it is the one most often needed.

Let us suppose that the Sybil has a penchant for telling passers-by which is the Greek muse for what. We might write:

> After asking the Sybil about a topic listed in the Table of Sybil's Replies, say "The Sybil declaims for a while, the gist being that the muse in question looks after [muse entry]."

We can then provide a simple table giving her responses:

> Table of Sybil's Replies

> Topic | Muse
> "calliope" | "epic poetry"
> "clio" | "history"
> "erato" | "love poetry"
> "euterpe" | "music"
> "melpomene" | "tragedy"
> "polyhymnia" | "sacred poetry"
> "terpsichore" | "dancing"
> "thalia" | "comedy"
> "urania" | "astronomy"
> "monica" | "tidiness"
> "phoebe" | "massage"
> "rachel" | "oval hair-cuts"

Topics can use the full range of abilities of the "understanding" system which Inform uses to parse text, and which will be the subject of a later chapter. For now, note that the Sybil's topics might equally include "flora/eve" (matching the single word "flora" or the single word "eve"), or something more elaborate such as:

> "Bridget" or "Bridge" or "Bridget Jones"

See Understand for the system Inform uses to parse text

266
| Example Merlin A REMEMBER command which accepts any text and looks up a response in a table of recollections. |
RB

267
| Example The Queen of Sheba Allowing the player to use question words, and using that information to modify the response given by the other character. |
RB

> Suppose we want the player to ask questions of slightly more complexity - we might want to build in a system that understood "who", "what", "where", and "when", for instance. We could use a topic table for this, too: "The Queen of Sheba" Interrogative is a kind of value. The interrogatives are who, what, when, where, how, and why. Current question is an interrogative that varies. After asking someone about something: respond to the question. After answering someone that something: respond to the question. After telling someone about something: say "You're here to ask questions and test Solomon's wisdom, not to give him a sample of your own." Table of Wise Answers
> topic | question type | reply
> "rain/weather/clouds/cloud/rains" | what | "'Clouds are a disturbance made by the paths of birds,' Solomon replies. 'The air beaten by their wings becomes agitated, as when a river is stirred and the mud churns up.'"
> "rain/weather/clouds/cloud/rains" | where | "'Weather is contained in a great silk bag which holds in the heavens,' replies Solomon."
> "hunger/food/eating" | when | "'Sorry, are you getting hungry?' he says, and rings a bell to summon servants."
> "hunger/food/eating" | why | "'Men were made to need food in order that they must farm and cook and dine together,' Solomon replies. 'Otherwise, they might live apart, each sufficient in himself. But no man can feed himself alone all through his life.'"
> "Solomon/he/himself" | who | "'As you see,' he says, holding out his arms to each side."
> "Solomon/he/himself" | what | "'I am an ordinary man,' he answers."
One of the nice things about this system is that it only resets the "current question" when we get a new question word. For instance, this test will produce different replies to the question about Solomon himself, because the second time he is still in the mode of answering "what" questions: Test me with "ask solomon about himself / ask solomon what rain is / ask solomon about himself". If Solomon is to live up to his reputation at all, his wisdom table will have to be quite a bit longer - though one also would want to be careful, because forcing the game to cycle through a really immense table could be quite time-consuming. In fact, for the sake of this example, let's reward the player for managing to stay within the (narrow) range of Solomon's knowledge: The Hall of Almug Tree Pillars is a room. "The pillars of the room are made of almug tree, the ceiling made of silk and the floor of glass." Solomon is a man in the Hall of Almug Tree Pillars. Solomon has a number called wisdom. The wisdom of Solomon is 0. Every turn: if the wisdom of Solomon is 3: say "Truly, Solomon has answered all your questions, and his wisdom is even as great as you had heard!"; end the story saying "Your heart beats strangely fast". When play begins, say "'Oh, you've arrived,' says Solomon." In a real game we'd need to be a great deal subtler. All the same, if we have a character of quite limited resources to present to the player, it's a good idea to give the player some incentive to stay on topic, ask questions the character can answer, and generally interact within the parameters we're prepared for. Now, this last bit requires some trickery from later chapters, particularly those on Understanding and Activities, to pull the question words out of the player's command: After reading a command: if the player's command includes "[interrogative]", now the current question is the interrogative understood. To respond to the question: repeat through the Table of Wise Answers: if the topic understood includes topic entry: if the current question is the question type entry: say "[reply entry][paragraph break]"; increment the wisdom of Solomon; rule succeeds; say "Solomon looks blank, appalled by a question for which he was not prepared."; end the story saying "You have befuddled Solomon!" Understand "ask [someone] [text]" as asking it about. And now we have a game that will accept (though not always respond very sensibly to) questions of almost any form we might put to another character: ASK SOLOMON WHAT RAIN IS will be answered, but then again, it won't be distinguished from, say, ASK SOLOMON WHETHER THIS PERSISTENT RAIN IS A DIVINE PUNISHMENT OR WHAT. All the same, a system that allowed the player a bit more specification of questions than simple keyword-use might be useful in a mystery game, for instance, where we might want to let our detective conduct inquiries into specific details. An alternative approach to the rather free one above would be to force the player to use only questions of the form WHAT IS RAIN? or WHO ARE YOU?: this would cut down on false-positive matches. But we might still choose to store the responses in a table of this type.

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| Example Questionable Revolutions An expansion on the previous idea, only this time we store information and let characters answer depending on their expertise in a given area. |
RB

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