Am Do., 21. Feb. 2019 um 10:17 Uhr schrieb Alex Shinn <xxxxxx@gmail.com>:
>
> On Thu, Feb 21, 2019 at 3:22 PM Marc Nieper-Wißkirchen <xxxxxx@gmail.com> wrote:
>>
>> Am Do., 21. Feb. 2019 um 05:01 Uhr schrieb Alex Shinn <xxxxxx@gmail.com>:
>> >
>> > 2019年2月21日(木) 6:26 Marc Nieper-Wißkirchen <xxxxxx@gmail.com>:
>> >>
>> >>
>> >> P.S.: I am currently working on an alternative implementation for SRFI
>> >> 159; that's why I have been finding all the minor issues I have been
>> >> reporting recently. (Actually, writing an independent implementation
>> >> for a SRFI looks like a great way to verify it.)
>> >
>> > That's fantastic. If not too late, I recommend using CPS so you don't need continuations.
>>
>> For "trimmed/lazy", one has to jump out of a running formatter. If all
>> formatters were composed using the primitive "each", I could thread an
>> explicit continuation argument through the environment monad to
>> implement "trimmed/lazy" without call/cc.
>
>
> I think it's fine to use call/cc for trimmed/lazy, I was thinking of columnar.
>
>>
>> Why do you suggest to refrain from first-class continuations, by the
>> way? They are a part of Scheme after all.
>
>
> Mostly to have and compare the alternate implementation strategy,
> and I suspect it may be less hairy.

I will let you know when I will have found the time to implement (show
columnar).

Hopefully, all this will be helpful for a future revised SRFI with
hygienic state vars.

>
> I think the fact that we can implement columnar portably on top of
> the base SRFI is a testament to the power of first-class continuations.

Indeed!

Marc

>
> --
> Alex
>