Functions

Functions are pieces of processing that can be defined in various places as a shorthand for often repeated processing steps. A function has a set of inputs (its requirements) and a set of output (what it yields). Functions need not be pure and often have side effects through the state changes of an entity.

Here’s an example of a function, named riddle, that requires a Subject(String) type and returns a Riddle (String) type. Presumably, it generates a riddle in any subject.

type Subject = String
type Riddle = String
function riddle is { requires {s: Subject}  yields { r: Riddle } }  

Functions have applicability across several RIDDL definitions:

• Context APIs - Contexts can define functions for use within their API handler.
• Handler - As utilities in a handler to encapsulate repeating logic from an on clause
• Allow internal entity processing to be specified as part of an interaction
• etc.

Further Content: TBD