• J Anderson (30/30) Dec 10 2003 As I see it there are 3 camps on the default switch issue
• Berin Loritsch (12/20) Dec 10 2003 -1. I don't like the idea because the behavior is not intuitive.

J Anderson <REMOVEanderson badmama.com.au> writes:

As I see it there are 3 camps on the default switch issue

No exception (C)
Mandatory default
Default exception

This is an attempt to go half-way between the No exception and default 
exception camps.

This is probably not a new idea, but here goes.

Default exception occurs when the user write default: with nothing after it.

val = 10;

switch (val)
{
case 5: break;
case 6: break;
default: //causes exception
}

switch (val)
{
case 5: break;
case 6: break;
default: break; //no exception
}

switch (val)
{
case 5: break;
case 6: break;
//no exception
}

Con: The problem with this is that people won't be compelled to use the 
"cool" default exception and so it may become hidden under the blanket.

-Anderson

Berin Loritsch <bloritsch d-haven.org> writes:

J Anderson wrote:

 As I see it there are 3 camps on the default switch issue
 
 No exception (C)
 Mandatory default
 Default exception
 
 This is an attempt to go half-way between the No exception and default 
 exception camps.

-1.  I don't like the idea because the behavior is not intuitive.

Perhaps a "bounded_switch" would be a nice way to make it obvious
what will happen when the default case is not handled.

Maybe an additional parameter:

switch(val) : bounded {}
switch(val) : unbounded {}

switch(val, true); // bounded == true
switch(val, false); // bounded == false

Anyhoo, I am not going to spend too much more energy on this, it is very
clear that Walter will do what he will do.  Since I am not writing the
compiler, there is only so much say I have in the matter.