Extra Supplies
Example 124
★★Suppose we have a supply closet in our game from which the player is allowed to take red pens. To keep modeling simple, we only allow him to have one in play at a time, and we test this by seeing whether the red pen is "off-stage" before moving it to his possession.
This approach might seem no different from having a single red pen sitting in the closet, but it may be preferable, for two reasons. First, it's not very plausible for a supply closet to contain nothing but a single red pen (well, assuming a well-regulated supplier, anyway); and second, it gives the player a way to get a new red pen should the original be destroyed in a tragic handwriting accident.
"Extra Supplies"
The Supply Closet is a room. A supply of red pens is in the Supply Closet. Understand "pen" as the supply of red pens when the red pen is not visible.
There is a red pen.
Instead of taking the supply of red pens:
if the red pen is off-stage:
move the red pen to the player;
say "You help yourself to a fresh red pen.";
otherwise:
say "You're only allowed one pen at a time. The department secretary is very strict."
South of the Supply Closet is the Furnace Room. The incinerator is a thing in the Furnace Room. It is a container. "The incinerator is here, working full blast."
After inserting something into the incinerator:
now the noun is nowhere;
say "A fiery blast consumes [the noun]!"
Test me with "get pen / i / get pen / get supply / s / put pen in incinerator / n / get pen".
Test me with "get pen / i / get pen / get supply / s / put pen in incinerator / n / get pen".
Supply Closet
You can see a supply of red pens here.
>(Testing.)
>[1] get pen
You help yourself to a fresh red pen.
>[2] i
You are carrying:
a red pen
>[3] get pen
You already have that.
>[4] get supply
You're only allowed one pen at a time. The department secretary is very strict.
>[5] s
Furnace Room
The incinerator is here, working full blast.
>[6] put pen in incinerator
A fiery blast consumes the red pen!
>[7] n
Supply Closet
You can see a supply of red pens here.
>[8] get pen
You help yourself to a fresh red pen.
You can see a supply of red pens here.
>(Testing.)
>[1] get pen
You help yourself to a fresh red pen.
>[2] i
You are carrying:
a red pen
>[3] get pen
You already have that.
>[4] get supply
You're only allowed one pen at a time. The department secretary is very strict.
>[5] s
Furnace Room
The incinerator is here, working full blast.
>[6] put pen in incinerator
A fiery blast consumes the red pen!
>[7] n
Supply Closet
You can see a supply of red pens here.
>[8] get pen
You help yourself to a fresh red pen.