FW: Switch statements again

[John Roth]

"Bengt Richter" <bokr at oz.net> wrote in message
news:b05r5n$oan$0 at 216.39.172.122...
> On Wed, 15 Jan 2003 18:21:40 -0500, Steven Scott
<bodoni26 at resnet.gatech.edu> wrote:
>
> >Quoting Steven Scott <Steven.Scott at Synchrologic.com>:
> >>=20
> >> If/elif/else remains the most common method.  If Python ever gains
> >> something
> >> like a switch statement you can bet the farm it won't have a "fall
thru=
> >"
> >> feature though, so the way you've coded your C switch statement
wouldn'=
> >t
> >> work.
> >>=20
> >
> >but the absolute /only/ reason you'd use a switch over an if (besides
> >looking better) is fall through.
> >
> Well, if you look at the code for an optimized C switch I think you'll
> find another reason. I.e., if you can predetermine that all the switch
> case _constants_ form a compact sequence of values, you can generate a
> computed jump through a table that is a lot faster than a series of
> conditional jumps, and even in cases where you have to introduce
conditional
> jumps for boundary cases you may still gain.

If all of the switch case _constants_ are single constants, you can use
a dictionary or a list of functions.

And I'd agree that I don't want fall through. Ever. It creates difficult
to
find bugs.

John Roth
>
> Regards,
> Bengt Richter