Creating Interactive Fiction with Inform 7

Notes on Chapter 07 - Logic and Control

This chapter introduces the syntax required to:

Use block indentation to format complicated logical tests
Use variables to simplify logic
Unlist a rule to resolve a bug
Create kinds of value and access the value before and the value after
Create named phrases and phrases to decide
Create phrases with variable inputs
Create and use list variables
Add items to a list using add to and optional if absent
Remove items from a list using remove from and optional if present
Conditionally check if item is listed in a list
Return the number of items in a list with number of entries
Sort the items in a list using sort with optional in random order
Sort the items in a list using reverse
Modify the size of a list using truncate
Loop through a list using repeat running through
Declare various kinds of number values using units with the specifies assertion
Compare numbers with math symbols or words
Perform basic arithmetic on numbers written out or with symbols
Get the remainder of the division operations with the remainder after dividing
Increment or decrement a number with increase by or decrease by
Display a number in words
Round a number using to the nearest followed by the unit
Use random numbers and random chances
Select random rooms, objects, or kinds
Display random text

There is a rule in the check going rulebook that prevents the player from going through an undescribed door.
There is a rule in the check going rulebook that prevents the player from removing something that is not worn. In my revised description of Crumblinb Concrete, the player learns that the door is boarded up. A player could likely attempt to remove boards which resulted in a bug. The interpreter responded You aren't wearing the boarded-up door.. Resolving this required unlisting the rule and customizing the remove command.
There is a table that describes various randomness types including at random, then at random, and other options.
The three columns in the Kinds index tell you if the kind:
- can use a repeat loop
- has props (or, properties)
- can implement understand rules