 | ||
|---|---|---|
 | Chapter 5. Patterns |  |
| 5.6. Call Pattern | 5.7. Cons Pattern | 5.8. As Pattern |
| ||
|---|---|---|
| | Chapter 5. Patterns | |
| 5.6. Call Pattern | 5.7. Cons Pattern | 5.8. As Pattern |
The cons pattern matches the head and the tail of a nonempty list.
When a cons pattern Ph:Pt
is matched against a list type List[T],
pattern Ph is matched against type T,
producing typing context Γh, and
pattern Pt is matched against type List[T],
producing typing context Γt.
The typing context produced by the whole match is Γh ∪ Γt.
{- Publish the head and tail of a list as a tuple -} val a = [1, 2, 3] a >x:y> (x, y) {- OUTPUT: (1, [2, 3]) -}