This patch make sure that function and macro definitions, as well as
do-blocks, end with an explicit `return` statement before the last
expression in the body. The following exceptions are made:
- If the last expression is a `for` or `while` loop (which both always
evaluate to `nothing`) `return` is added *after* the loop.
- If the last expression is a `if` or `try` block the `return` is only
added in case there is no `return` inside any of the branches.
- If the last expression is a `let` or `begin` block the `return` is
only added in case there is no `return` inside the block.
- If the last expression is a macro call the `return` is only added in
case there is no `return` inside the macro.
- If the last expression is a function call, and the function name is
`throw`, `rethrow`, or `error`, no `return` is added. This is because
it is pretty obvious that these calls terminate the function without
the explicit `return`.
Since adding `return` changes the expression that a macro will see, this
rule is disabled for function definitions inside of macros with the
exception of some known ones from Base (e.g. `@inline`, `@generated`,
...).
Closes#43.
Fredrik Ekre