Re: Why is break not syntactically required to be the last statement in a block (anymore)?

[Lars Müller <appgurulars@...>]

    To throw an alternative syntax in the pot: Labeling loops / blocks.
    This is how you can continue / exit outer loops in languages like Go
    or Java: Loops can be labeled with "<name>: <loop>" and
    continue/break take an optional name:
    
foo: for ... do
    while ... do
        continue foo
    end
end

bar: for ... do
    repeat
        break bar
    until ...
end

> As I
>       recall it, this is the right explanation for the current
>       situation.
>       
>       
>       FWIW, I'd still like "break" to be improved to manage multi-level
>       breaks, even as syntactic sugar for an hidden goto+label
>       definition.
>       
>       I don't despise GOTOs, but I think that using a goto to exit a
>       multilevel loop is very error prone, especially if the label is
>       far away from the goto, which is not so rare a case when algorithm
>       with 3 or 4 nested loops are used (and this is really the case
>       where you would find a multilevel break really useful).
>       
>       
>       Semantically a multilevel break is a very clear program action,
>       which should be understandable at the break site ("I want to exit
>       multiloop").
>       
>       Using a goto at that same point must rely on "meta" information to
>       convey the same meaning to the code reader, such as a comment or a
>       descriptive label, but these may be misleading (possibly
>       ambiguous: "goto start", to exit a multiloop).
>       
>       
>       I would welcome a syntax like "break 4", to exit four loop levels.
>       
>       WRT the parser lookahead capabilities, maybe an uglier syntax
>       could avoid excessive lookahead, like "break<4>". After all
>       with Lua 5.4 and const/to-be-closed vars the syntax has already
>       been uglified a lot, IMHO.
>       
>       
>       An alternative would be sort of like "relative jumps" (breaks are
>       essentially that):
>       
>       
>       goto +1 = break (jumps just after the end of current loop body)
>       
>       goto +2 = break 2 (jumps just after the end of the innermost
>       enclosing loop body)
>       
>       
>       This could be generalized to implement a "continue" statement
>       (multilevel too):
>       
>       
>       goto -1 = continue (jumps at the end of current loop body)
>       
>       goto -2 = continue 2 (jumps at the end of the innermost enclosing
>       loop)
>       
>       
>       (and maybe someone could come up with a syntax that's nicer than
>       in these ramblings of mine :-).
>       
>