Macros are introduced early in Rust for a couple reasons.
1. println!() is a macro, so if you want to print anything out you need to grapple with what that ! means, and why println needs to be a macro in Rust.
2. Macros are important in Rust, they're not a small or ancillary feature. They put a lot of work into the macro system, and all Rust devs should aspire to use and understand metaprogramming. It's not a language feature reserved for the upper echelon of internal Rust devs, but a feature everyone should get used to and use.
Hard disagree, macros almost always lead the "too clever for you own good" even when the macro system is safe. Macros should always be used sparingly, and I think that Rust teeters on the edge of encouraging too much complexity for the sake of convenience. As a systems programmer I am allergic to unnecessary levels of indirection that make it more difficult for me to reason about what the system is actually doing and how performance and hardware interaction will be affected.
I agree that if you're using macros to create unnecessary levels of indirection that make things more difficult to reason about, that's not advisable. One shouldn't do that with macros or any other abstraction.
With functions for instance, sometimes people get carried away very straightforward linear code, and atomize it into a hundred little functions that all call one another, all in the name of reducing code duplication. Doing so is an abuse of functions, but one wouldn't say that functions should be used sparingly.
I think that macros are an area where many programmers don't have a lot of experience, and so they also throw out some best practices in order to wrap their heads around what they're doing.
But macros can be very helpful if properly applied, and Rust makes that more ergonomic, and safe, to do.
For example, if I have to write 100 functions that all are similar in structure, but have a slightly different function signature. I would reach for a macro. I don't think it reduces clarity at all, and it increases maintainability because I don't have to change code in 100 functions if an adjustment needs to be made.
Another area where macros is very useful is in creating DSLs within Rust. This is usually the domain of LISPs, but it's an ergonomic way to write tests little scripts.
1. println!() is a macro, so if you want to print anything out you need to grapple with what that ! means, and why println needs to be a macro in Rust.
2. Macros are important in Rust, they're not a small or ancillary feature. They put a lot of work into the macro system, and all Rust devs should aspire to use and understand metaprogramming. It's not a language feature reserved for the upper echelon of internal Rust devs, but a feature everyone should get used to and use.