This directory defines the primary data structures used in the compiler
using the `define-struct' macro defined in the struct directory.

Structures are divided into the following catagories:

Basic structures: (basic-structs)
  References to variables, data constructors, classes, type constructors
    All references contain the name of the object referred to and a
    field that will receive the actual definition object when scoping
    has been resolved.
  Fixity: (l | n | r, Int)

Module structures: (module-structs)
  The module ast, import & export related ast's, and fixity definition.

Type system structures: (type-structs)
  The representation of data types and the type related declarations:
  type, data, class, and instance.

Value declarations: (valdef-structs)
  
Expressions: (expr-structs)

Definitions: (definition-structs)

Flic structures: (flic-structs)