Re: [Chicken-users] Re: matchable egg ticket #487

[Alex Shinn]

Fixed upstream, including http://synthcode.com/scheme/match-cond-expand.scm,
which is basically suitable for Chicken modulo the module syntax.

Do we want the latest version for Chicken (with tree patterns and ..1),
or should I just patch this one bug?

-- 
Alex


On Tue, Jan 25, 2011 at 8:32 AM, Alan Post <address@hidden> wrote:
> On Tue, Jan 25, 2011 at 07:51:12AM +0900, Alex Shinn wrote:
>> On Sun, Jan 23, 2011 at 3:01 PM, Alan Post <address@hidden> wrote:
>> >
>> > I've just come across a bug in the matchable egg which I've
>> > documented in ticket #487:
>> >
>> >  http://bugs.call-cc.org/ticket/487
>> >
>> > A call is made to |length| even when the input isn't a list if a
>> > production contains |...|.
>>
>> Thanks, those tail-patterns are a relatively recent extension
>> and this is indeed a bug.  I'll fix it ASAP.
>>
>
> I tried using |...| as something of a last resort trying to match a
> tail pattern, thinking "I wonder if the ... in the documentation is
> literal, rather than elision.  I couldn't figure out any other way
> to match a tail pattern.  Given that they are new, I see now I may
> have used something that wasn't documented, which clears up a
> confusion of mine.
>
> I wrote such a lengthy test case just to prove to myself that ...
> was working like I expected it to.
>
> These tail-pattern matches are a time-saver for me.  In one
> particular case I have a complex set of boolean variables that I use
> to generate code, and I use match later on in the routine in order
> to determine what happened, rather than reusing the boolean
> variables to see if I made a modification.
>
> Basically, I have:
>
>  if A do x, y
>  if B do y, z
>  if C do x, z
>
> and I mant to make sure I do x, y, or z only once, even if there are
> multiple variables set that require it.
>
> Thank you Alex!
>
> -Alan
> --
> .i ko djuno fi le do sevzi
>