That whole example feels like a strawman, from my (maybe limited) experience something that's rather the exception than the norm.

First, lifetimes are elided in most cases.

Second, the curly braces for the closure are not needed and rustfmt gets rid of them.

Finally, the "map" on result can be replaced with a return statement below.

So, in the end we get something like:

  Trying::to_read(syntax, |like| this.can_be(maddening))?; 
  Ok(())