To go further, if you wonder how to make this work for `match` and
inheriting, see this stackoverflow question:
https://stackoverflow.com/questions/55262818/how-to-override-a-struct-constructor-while-still-providing-the-struct-metadata-f
On Mon, Mar 18, 2019 at 3:08 PM Marc Kaufmann
wrote:
>
While I did know that I could define my own, I was going to do it while
providing-out another function make-fish and make-shark, but it's nice to
know that this allows me to locally define make-fish, while it looks to the
outside like (fish ...).
Thanks to including sufficient numbers of mundane
Once you discover that the default constructor for a struct is just a
simple procedure that was generated for you, it's not that big of deal to
just make your own and export it like this:
(provide
(except-out (struct-out fish) fish)
(rename-out (make-fish fish)))
All the code relying on it
Yes, I saw that, the problem is that I want to be able to set a
(potentially different) default value for the sub-type shark than for the
sub-type guppy. So if I set the value to 'big for all `fish`, then I can't
do that. Essentially, I'd need an #:auto for every sub-type, but the #:auto
refers to
Maybe #:auto/#:auto-value is what you want:
```
(struct fish (name [size #:auto])
#:auto-value 'big
#:transparent)
(struct shark fish (scares-people?) #:transparent)
(define white-shark (shark "The big white" #t))
```
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Hi all,
suppose I have a struct `(struct fish (size name) #:transparent)` and a
sub-type `(struct shark fish (scares-people?) #:transparent)`. What if I
want all sharks to have size 'large by default whenever I create one, so
that I create them via:
(define white-shark (shark "The big white"
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