Steven Schveighoffer, el 22 de junio a las 07:26 me escribiste:
> On Mon, 21 Jun 2010 20:40:14 -0400, Adam Ruppe
> <destructiona...@gmail.com> wrote:
>
> >What's the point of a switch without implicit fallthrough?
>
> Maintenance. Using if statements instead of switch, you have to
> repeat the value to test for each of the cases. If you want to
> change the value being tested, it's one change. And your workaround
> using a delegate is not very appealing.
And it's a bit comfortable when used with expressions that should be
evaluated just one:
switch (foo()) {
case xxx:
...
case yyy:
...
}
vs
auto tmp = foo();
if (tmp == xxx) {
...
else if (tmp == yyy) {
...
}
> I'll also point out that popular languages have a switch statement
> and don't allow implicit fallthrough, meaning that 100% of switch
> statements do not have fallthrough. And switch is used quite often
> in those languages too, so at least some people think it has use
> besides allowing implcit fallthrough.
>
> I think mostly it's because the meaning of it is so easy to
> understand when reading/writing it. When you see a switch, you know
> what it is and what it isn't. An if statement has many
> possibilities and must be read more carefully.
Like for/while vs goto and foreach vs while/for. They are
specializations for common uses. It helps both the programmer to
write/read more clear code and the compiler to generate more efficient
code because they have a more defined semantics and it can make more
assumptions.
--
Leandro Lucarella (AKA luca) http://llucax.com.ar/
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