37b0549730
Adds a new kind of pattern C(*) where C is a constructor that may have any number of fields. This pattern matches any value constructed with C, without binding names for any of the fields. Closes #1701.
21 lines
586 B
Rust
21 lines
586 B
Rust
enum pattern { tabby, tortoiseshell, calico }
|
|
enum breed { beagle, rottweiler, pug }
|
|
type name = str;
|
|
enum ear_kind { lop, upright }
|
|
enum animal { cat(pattern), dog(breed), rabbit(name, ear_kind), tiger }
|
|
|
|
fn noise(a: animal) -> option<str> {
|
|
alt a {
|
|
cat(*) { some("meow") }
|
|
dog(*) { some("woof") }
|
|
rabbit(*) { none }
|
|
tiger(*) { some("roar") }
|
|
}
|
|
}
|
|
|
|
fn main() {
|
|
assert noise(cat(tabby)) == some("meow");
|
|
assert noise(dog(pug)) == some("woof");
|
|
assert noise(rabbit("Hilbert", upright)) == none;
|
|
assert noise(tiger) == some("roar");
|
|
} |