How do you actually find out *how* to use an interface in Julia, like the concept of iterator "end"?

[raman_kumar]

@sgaure

Iterators are sort of an exception, in that the compiler/parser/lowering-engine actually rewrites for loops (literally) into while loops, so this particular interface is in a sense part of the language.

Is there contradiction about loops conversion between above and below post?

Understanding iterate() documentation is tough

Behind the scenes, there’s no such thing as a for loop or while loop. It’s a bunch of gotos in intermediate code, LLVM br-anches, and ultimately native jumps. You can check with Meta.@lower or the @code_### reflection macros. And no. First, your version omits the iter variable and adds extra stuff like @show, which are generally liberties you should avoid for documentation. Second, the for loop does not create a global variable next or the local variable state/index*, so it’s obviously not th…