InputTypeRequest and others represent consts for Directives.

NamespaceDefault and others represent conts for namespaces.

Alias is the parsed version of an entry in the `With` array from a CallableFn If you do user: activeUser, then activeUser is the state key and user is the key that gets put into the function's state (i.e.

CallableFn is a fn along with its "variable name" and "args".

Directive describes a set of functions and a set of handlers that take an input, and compose a set of functions to handle it.

Executable represents an executable step in a handler.

Handler represents the mapping between an input and a composition of functions.

Input represents an input source.

Runnable is the structure of a .runnable.yaml file.