Sometimes, it is desirable to have the type system carry more information than normal. If we look at the process of compilation, types occupy a space between the program code and the program executable. The code can take the form of text files before compilation or an abstract syntax tree such as those manipulated by Rust macros. Program executables consist of the resulting combination of all Rust primitives like expressions, functions, datatypes, traits, and so on.
Right in the middle, it is possible to introduce a new concept called algebraic data types (ADTs). ADTs are technically an extension of Rust primitives, though it is important to note how much extra type information is used for ADTs. ...
