Add explanation that single-expression blocks cannot contain statements (like class, for, if, import, return, var, while) since they don't produce values, and show how to use a newline to create a block with a single statement instead. Fixes #390.
Add explanation that single-expression blocks cannot contain statements (like class, for, if, import, return, var, while) since they don't produce values, and show how to use a newline to create a block with a single statement instead. Fixes #390.