figure out the prefered error handling method for the code generation phase

[foresterre]

background info:

• https://docs.rs/syn/1.0.7/syn/parse/struct.ParseBuffer.html#method.error
• https://docs.rs/syn/1.0.7/syn/struct.Error.html#method.to_compile_error
• https://doc.rust-lang.org/std/macro.compile_error.html