Am Do., 8. Okt. 2020 um 22:29 Uhr schrieb Wolfgang Corcoran-Mathe
<xxxxxx@sigwinch.xyz>:
>
> On 2020-10-08 22:06 +0200, Marc Nieper-Wißkirchen wrote:
> > Am Do., 8. Okt. 2020 um 21:59 Uhr schrieb Wolfgang Corcoran-Mathe
> > <xxxxxx@sigwinch.xyz>:
> >
> > > On 2020-10-08 21:52 +0200, Marc Nieper-Wißkirchen wrote:
> > > > Am Do., 8. Okt. 2020 um 21:45 Uhr schrieb Wolfgang Corcoran-Mathe
> > > > <xxxxxx@sigwinch.xyz>:
> > > >
> > > > > Yes.  This is one reason why I'm rather sad that vector-set! can't be
> > > > > linear update--there are plenty of immutable implementations of vectors
> > > > > which can guarantee O(log n) access.
> > > >
> > > > What do you mean by linear-update here?
> > > >
> > > > Do you mean a non-destructive update instead?
> > >
> > > Yes, of course.  I meant "linear update" in the sense of SRFI 1's
> > > use of the term:
> > >
> > > > A "linear update" procedure is allowed -- but not required -- to
> > > > side-effect its arguments in order to construct its result.
> >
> > But Scheme's vector-set! is already linear-update in this sense, more
> > precisely, the following procedure is:
> >
> > (define (vector-amend! vec i obj)
> >   (vector-set! vec i obj)
> >   vec)
> >
> > Or do you complain about the existence of vector-set!, which means
> > that Scheme vectors cannot be truly immutable?
>
> Yes, that's a bit limiting, in my humble opinion.  And I do tend

We could experiment with a Scheme that has no set!, no set-car!, no
set-cdr!, no vector-set! and no string-set!.

> to use vector-amend! in my own work, since it allows procedures
> written in functional style to be easily adapted to vectors.
>
> But this is tangential.  I do appreciate the implementation
> freedom that linear update semantics provide.
>
> --
> Wolfgang Corcoran-Mathe  <xxxxxx@sigwinch.xyz>
>
> "All this currying's just a phase, though it seldom hinders."
> --Fritz Ruehr