instancefor
Instancefor is a declarative construct used in some programming libraries to specify how to generate a concrete instance of a given type. It associates a type with a generator function or recipe that constructs values, typically for testing, mock data, or fixtures. The goal is to separate the data structure definition from the logic used to instantiate it in different contexts.
Usage and syntax commonly involve declaring an instancefor block or directive that binds a type to a
generator = User(id = autoId, name = autoName, email = autoEmail)
This defines how to create a User value automatically. Many implementations also support overrides or overrides
instancefor User with overrides { name = "Alice" }
Common patterns and capabilities include default field values, nested generation for composite types, and integration with
Relation to other concepts: instancefor is related to factory patterns, builders, and fixture libraries. It shares
See also: factory, builder pattern, fixture, property-based testing, mock data generation.