Data Structures

Here are the data structures with brief descriptions:

function_definition	Represents the definition of a known function
FunctionApplication	A unit corresponding to an application of a function to a unit sequence
SimpleUnit	A simple unit, corresponding to, for example, ‘MHz’
unit_struct	A single parsed unit
UnitDef	Encapsulates per-syntax information about a unit
UnitExpression	The parsed version of a unit string