18.2. How activities work

§18.2. How activities work

All activities start, continue for a while and then finish: however, no activity ever runs on for more than a single turn. Several activities can be going on at the same time. For instance, suppose the following is printed as part of the description of a grocery:

You can see a banana, an apple and a star-fruit here.

At the moment when Inform prints "apple", two activities are under way: "listing contents of the Grocery", and "printing the name of the apple". The sequence of events was in fact:

say "You can see "
start listing contents of the Grocery
    say "a "
    start printing the name of the banana
        say "banana"
    finish printing the name of the banana
    say ", an "
    start printing the name of the apple
        say "apple"
    finish printing the name of the apple
    say " and a "
    start printing the name of the star-fruit
        say "star-fruit"
    finish printing the name of the star-fruit
finish listing contents of the Grocery
say " here."

The golden rule is: if activity B starts during activity A, it must also finish during activity A.

If we ever need to find out, we can always test:

if the printing the name activity is going on, ...
if the printing the name activity is not going on, ...

but as we shall see, it's usually simpler to attach "while printing the name" provisos to rules.

	Start of Chapter 18: Activities
	Back to §18.1. What are activities?
	Onward to §18.3. Rules applied to activities