# Intro

This section deals with the following specifications

* Specification of generic functions applicable in the Simantics framework
* Specification of functions attached to types (methods)
* Specification of functions with side-effects (operations or commands)
* Automatically generated code based on semantic model about functions (stubs)

## Specification

* Functions are objects implementing the interface `org.simantics.scl.runtime.function.Function`.
* We have a type `Value` (?) that can be adapted to an SCL value (in particular to a function).
* We have a relation `HasType` (?) Value -> String that specifies the SCL type of the value
* Operations are functions that return an object implementing `WriteResult`.