On 09/14/2011 10:51 PM, bearophile wrote:
Timon Gehr:
I think it is a bit mean to say the whole semantics is a mess,
The original C design is a mess with several traps, and successive things added
in D to the switch have increased the mess, they were designed from very narrow
points of view, with a lack of global vision:
1) The case x: .. case y: syntax is ugly, and it doesn't respect the semantics
of the .. in D that means a range open on the right.
That's subjective of course. It does not strike me as particularly ugly.
(if you'd rather see case x .. y+1:, I think that is exceptionally
ugly). The fact that the last case is included is a move to make it more
useful. What would you suggest?
2) The introduction of final switches is badly designed and not complete, so
the safety of the situation is not improved:
http://d.puremagic.com/issues/show_bug.cgi?id=5713
Yah, that is quite messy, but I think that can be fixed.
3) The recent improvements (that are patches on the stupid semantics of the C
switch) are buggy and need a patch:
https://github.com/D-Programming-Language/dmd/pull/370
QOI issue, not a fundamental design flaw. I am sure the patch will be
applied.
Switch is too much limited, ignoring other needs:
http://d.puremagic.com/issues/show_bug.cgi?id=596
I agree that it would be nice for switch to work on other types.
The other needs are better addressed by the introduction of a match
expression.
I'll never agree that the C switch is well (or even "well enough") designed.
Even a simple language as Pascal gets the case-of statement better than C.
'C switch' means 'jump table'. It does do that perfectly. ;)
switch statements and gotos provide nice means of writing highly
efficient code that still looks somewhat structured.
I'd like computed gotos in D. I have discussed with Walter often about this,
but he doesn't listen much on this.
+1.
Well, yes, but that is as expected. Would you expect a fall through
error on this code?
Have you run that code?
What is your point?
