Reference Guide: Core Types

Type Hierarchy

Mimi uses plain Julia structs and abstract types to define its core data structures. An abstract type hierarchy enables dispatch across related types. For example, ModelDef <: AbstractCompositeComponentDef <: AbstractComponentDef <: AbstractNamedObj. Methods can be written with arguments typed x::AbstractComponentDef to operate on leaf components, composites, and model definitions alike.

User-facing Types

1. Model: Contains a ModelDef, and after the build() function is called, a ModelInstance that can be run. The API for Model delegates many calls to either its top-level ModelDef or ModelInstance, while providing additional functionality including running a Monte Carlo simulation.

2. ComponentReference

[TODO]

1. VariableReference

[TODO]

Core Types

Several core types are defined in types/core.jl. Some of the important structs include:

1. ComponentId

   To identify components, @defcomp creates a variable with the name of the component whose value is an instance of this type. The definition is:

   julia struct ComponentId module_obj::Union{Nothing, Module} comp_name::Symbol end

2. ComponentPath

   A ComponentPath identifies the path from one or more composites to any component, using an NTuple of symbols. Since component names are unique at the composite level, the sequence of names through a component hierarchy uniquely identifies a component in that hierarchy.

   julia struct ComponentPath names::NTuple{N, Symbol} where N end