I sometimes find it convenient to be able to specify the "short-circuiting" of the "or" operator in the reverse order.

This happens in particular when I use the "and-let*" form, and I want to provide the default alternative:

Instead of

(or
(and-let* (...)
...)
default-value)

it might be preferable to write:

(otherwise default-value
(and-let* (...)
...))

where "otherwise" is defined trivially as

(define-syntax otherwise
(syntax-rules ()
((_) #false)
((_ expression) expression)
((_ expression . expressions)
(or (otherwise . expressions) expression))))

(so it effectively reverses the order of arguments to "or")

Do you think "otherwise" is a good name for this?
Or are there any alterantives that you'd recommend?

On Monday, October 11, 2021 at 11:38:20 AM UTC+2, godek....@gmail.com wrote:
> I sometimes find it convenient to be able to specify the "short-circuiting" of the "or" operator in the reverse order.
>
> This happens in particular when I use the "and-let*" form, and I want to provide the default alternative:
>
> Instead of
>
> (or
> (and-let* (...)
> ...)
> default-value)
>
> it might be preferable to write:
>
> (otherwise default-value
> (and-let* (...)
> ...))
>
> where "otherwise" is defined trivially as
>
> (define-syntax otherwise
> (syntax-rules ()
> ((_) #false)
> ((_ expression) expression)
> ((_ expression . expressions)
> (or (otherwise . expressions) expression))))
>
> (so it effectively reverses the order of arguments to "or")
>
> Do you think "otherwise" is a good name for this?
> Or are there any alterantives that you'd recommend?

If the goal is to reverse `or`, why not write `(or c b a)` instead of `(or a b c)`?

On Mon, 11 Oct 2021 02:38:18 -0700 (PDT), Maciek Godek
<godek.maciek@gmail.com> wrote:

>I sometimes find it convenient to be able to specify the
>"short-circuiting" of the "or" operator in the reverse order.
>
>This happens in particular when I use the "and-let*" form, and I
>want to provide the default alternative:
>
>Instead of
>
>(or
> (and-let* (...)
> ...)
> default-value)
>
>it might be preferable to write:
>
>(otherwise default-value
> (and-let* (...)
> ...))
>
>where "otherwise" is defined trivially as
>
>(define-syntax otherwise
> (syntax-rules ()
> ((_) #false)
> ((_ expression) expression)
> ((_ expression . expressions)
> (or (otherwise . expressions) expression))))
>
>(so it effectively reverses the order of arguments to "or")
>
>Do you think "otherwise" is a good name for this?
>Or are there any alterantives that you'd recommend?

In keeping with other wrappers, perhaps "with-default"?

YMMV,
George