Class predicate words - Factor Documentation (original) (raw)
With a handful of exceptions, each class has a membership predicate word, named class?. A quotation calling this predicate is stored in the "predicate" word property.
When it comes to predicates, the exceptional classes are:
| Class | Predicate | Explanation |
|---|---|---|
| f | [ not ] | The conventional name for a word which outputs true when given false is not; f? would be confusing. |
| object | [ drop t ] | All objects are instances of object |
| null | [ drop f ] | No object is an instance of null |
The set of class predicate words is a class:
predicate
predicate? ( object -- ? )
A predicate word holds a reference to the class it is predicating over in the "predicating" word property.
Implementation of class reloading:
reset-class ( class -- ) forget-class ( class -- ) forget-methods ( class -- )