The more I think about it, the more I like the
vector->range/vector-range pair. The first is conceptionally a
conversion function, the latter a constructor.

In this spirit, I would also want to suggest

(string-range STRING)

a range constructor that takes a string and does the obvious thing. As
with vector-range, the argument mustn't be modified later.

The rationale for adding string-range is special. There have been many
attempts to ensure O(1) reference to string characters, e.g. string
cursors, UTF-32 encoding, texts, immutable strings, ... Now,
string-range is a cheap and obvious solution.

An implementation. which has O(1) access time for whatever reasons, would define

(define (string-range s)
  (range (string-length s) (lambda (i) (string-ref s i))))

An implementation, which has O(n) access time for strings, would define

(define (string-range s)
  (vector-range (string->vector s)))

The nice thing is it is transparent for the user who just wants to
examine a string character-wise. He or she just has to work with
(string-range s) instead of s directly. The icing on the cake is that
the operations range-split-at and range-append, which may be used in
the further processing of the string, are extremely cheap compared to
string-copy and string-append.

Marc

Am Mi., 2. Sept. 2020 um 09:57 Uhr schrieb Marc Nieper-Wißkirchen
<xxxxxx@nieper-wisskirchen.de>:
>
> > Rename it to
> >
> > ivector->range
> >
> > ?
>
> Better suggestion:
>
> (vector-range VECTOR)
>
> wraps VECTOR in a range.
>
> (vector->range VECTOR)
>
> copies the vector first.
>
> The naming vector-range is consistent with numeric-range and other
> range-constructors we may conceive in the future.