syntax-e vs syntax->datum in 4.1.4 about fear-of-macros HOT 2 CLOSED

syntax-e and syntax->datum were discussed earlier, in 3.1: syntax->datum is syntax-e applied recursively.

You could use syntax->datum here instead. But using syntax-e expresses that we expect the syntax to be an identifier that results in a symbol. And if it isn't, there will be a compile-time error.

(The error message will talk about stuff inside the macro implementation, which isn't very helpful to a user of the macro. (We discuss that later. Hint: Using syntax-parse with the id class would be wonderful.) But at least it will be most proximate to the problem inside the implementation, i.e. it will "go wrong quicker".)

Does that help?

from fear-of-macros.

OK, I see. It looks to me like the compile-time error is the same, whether you use syntax->datum or syntax-e, but I guess avoiding the recursive application is a little more efficient, perhaps. It was just that the earlier definitions of hyphen-define/... in the sections above all used syntax->datum but at that point it switches to syntax-e and I wasn't sure if there was some special reason that syntax->datum couldn't be used there as well. Thanks!

from fear-of-macros.