model

maps : structure that supports acid-state, exact lookup and prefix lookup!-> ixset?
	packages
		map name -> package

	modules
		map full name
			-> map package/version
				-> module

	decls
		map name -> 
			map module ->
				map package/version
					-> decl

	types?
		type -> decls?

data
	package
		- name
		- version
		- local?
		- doc
		- all metadata (license, author, etc.)
		- component names
	component
		- name
		- type (library/executable/test/benchmark)
		- module names		
	module
		- name
		- package
		- version
		- component names
		- local?
		- doc
		- decls names
		- reexported modules/decls
	decl
		- name
		- module
		- package
		- version
		- parent decl name
		- child decls name	
		- local?
		- exposed?
		- type of data (function, type, constructor, etc)
		- type signature
		- flags
		- source
		- doc
		- uses -> map (name in code) -> qualified name (package, module, name, version range?)
		- usedBy -> list of qualified names (package, module, name, version range?)
		- related -> map type of relation -> list of qualified names (package, module, name, version range?)