[SR-13167] Parse: add parsing/syntax support for @differentiable(default, ...) #55609
Description
| Previous ID | SR-13167 |
| Radar | rdar://problem/69987999 |
| Original Reporter | @dan-zheng |
| Type | Sub-task |
Additional Detail from JIRA
| Votes | 0 |
| Component/s | Compiler |
| Labels | Sub-task |
| Assignee | None |
| Priority | Medium |
md5: dc508f6543b2cdff61b1f36c59bd25d9
Parent-Task:
- SR-13166 Default derivative implementations for protocol requirements
Issue Description:
See relevant section from the differentiable programming manifesto: https://github.com/apple/swift/blob/master/docs/DifferentiableProgramming.md#default-derivatives-and-transposes.
The optional "default" component should appear after the optional "linear" component and before the optional "wrt:" clause.
The following ~fully elaborated @differentiable attribute should parse and pass syntax testing (but doesn't type-check).
@differentiable(linear, default, wrt: (x, y) where T: FloatingPoint)
func foo<T>(_ x: T, _ y: T) -> T {}