These are structures that must be implemented by the standard library. They should be implemented such that one can import all of them by importing "std" or one may import specific ones by importing "std.TYPE"
TODO: Generic data types: asm, markup, model, sound, composite
TODO: Text contexts, object notation: xml, json, yaml, rpl
TODO: Text contexts, tables: csv
TODO: Text contexts, formatted text: rtf
TODO: Text contexts, other: html