Bill Page wrote:
>
> The following simple patch
>
> https://github.com/billpage/fricas/commit/dad89022088a2a9c410344d10b1cda06773a61f9.patch
>
> adds value constructor functions to tagged Unions in order to support
> Unions where the same type appears more than once. I noticed that the
> current hyperdoc documentation for Union already states that one
> purpose of tags is to "disambiguate" branches that have the same type
> but the current implementation does not support it.
>
> Arguably one could also implement this using the 'setelt!' analogous
> to the idiom implemented in Record but the following use-case
>
> (7) -> z:Union(f1 : Void, f2 : Void)
> Type: Void
> (8) -> z:=f2(void())
>
> (8) "()"
> Type: Union(f1: Void,f2: Void,...)
> (9) -> z case f2
>
> (9) true
> Type: Boolean
That works. However:
(4) -> f2(void())$Union(f1 : Void, f2 : Void)
The function f2 is not implemented in Union(f1: Void,f2: Void) .
(4) -> f2(void())
There are no library operations named f2
Use HyperDoc Browse or issue
)what op f2
to learn if there is any operation containing " f2 " in its name.
Cannot find a definition or applicable library operation named f2
with argument type(s)
Void
Perhaps you should use "@" to indicate the required return type,
or "$" to specify which version of the function you need.
so more is needed to have consistent support for such feature.
--
Waldek Hebisch
--
You received this message because you are subscribed to the Google Groups
"FriCAS - computer algebra system" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to fricas-devel+unsubscr...@googlegroups.com.
To post to this group, send email to fricas-devel@googlegroups.com.
Visit this group at https://groups.google.com/group/fricas-devel.
For more options, visit https://groups.google.com/d/optout.
