The `@transpose(of:)` attribute registers a function as a transpose of another
function. This patch adds the `@transpose(of:)` attribute definition, syntax,
parsing, and printing.
Resolves TF-827.
Todos:
- Type-checking (TF-830, TF-1060).
- Enable serialization (TF-838).
- Use module-qualified names instead of custom qualified name syntax/parsing
(TF-1066).
Previously we had a request for this in
IDETypeChecking, but this wasn't used for queries
made from Sema. Move the request into Sema, and
move `hasDynamicMemberLookupAttribute` onto
TypeBase.
This is needed to build with VS2019:
```
swift\include\swift\AST\AutoDiff.h(172): error C2593: 'operator ==' is ambiguous
swift\include\swift\Basic\AnyValue.h(129): note: could be 'bool swift::operator ==(const swift::AnyValue &,const swift::AnyValue &)' [found using argument-dependent lookup]
swift\include\swift\AST\AutoDiff.h(172): note: or 'built-in C++ operator==(swift::AutoDiffDerivativeFunctionKind::innerty, swift::AutoDiffDerivativeFunctionKind::innerty)'
swift\include\swift\AST\AutoDiff.h(172): note: while trying to match the argument list '(const swift::AutoDiffDerivativeFunctionKind, const swift::AutoDiffDerivativeFunctionKind)'
```
The `@derivative` attribute registers a function as a derivative of another
function-like declaration: a `func`, `init`, `subscript`, or `var` computed
property declaration.
The `@derivative` attribute also has an optional `wrt:` clause specifying the
parameters that are differentiated "with respect to", i.e. the differentiation
parameters. The differentiation parameters must conform to the `Differentiable`
protocol.
If the `wrt:` clause is unspecified, the differentiation parameters are inferred
to be all parameters that conform to `Differentiable`.
`@derivative` attribute type-checking verifies that the type of the derivative
function declaration is consistent with the type of the referenced original
declaration and the differentiation parameters.
The `@derivative` attribute is gated by the
`-enable-experimental-differentiable-programming` flag.
Resolves TF-829.
This type wraps a DeclName, indicating that it is a reference to a declaration that exists somewhere else and it requires slightly “fuzzy” comparison (i.e. if it’s not compound, only the base names should be compared). DeclName::matchesRef() and MemberLookupTable::find() both now take a DeclNameRef instead of a DeclName.
This commit temporarily allows implicit conversion from DeclName; I’ll flip the switch on that in a later commit.
This feature is barely used and needs refactoring that would be outside the scope of this series of commits (see https://bugs.swift.org/browse/SR-11241).
Replaces `ComponentIdentTypeRepr::getIdentifier()` and `getIdLoc()` with `getNameRef()` and `getNameLoc()`, which use `DeclName` and `DeclNameRef` respectively.
So that DeclName can have a spare bit, allowing it to be used in places where we’re currently using PointerIntPair<Identifier, 1> or PointerUnion<Identifier, Whatever>.
This change adds UnresolvedDotExpr::createImplicit() and UnresolvedDeclRefExpr::createImplicit() helpers. These calls simplify several tedious bits of code synthesis that would otherwise become even more tedious with DeclNameRef in the picture.
State the previously unstated nested type requirement that CodingKeys adds to the witness requirements of a given type. The goal is to make this member cheap to synthesize, and independent of the expensive protocol conformance checks required to append it to the member list.
Further, this makes a clean conceptual separation between what I'm calling "nested type requirements" and actual type and value requirements.
With luck, we'll never have to use this attribute anywhere else.
The `@derivative(of:)` attribute registers a function as a derivative of another
function. This patch adds the `@derivative(of:)` attribute definition, syntax,
parsing, and printing.
Resolves TF-826.
Todos:
- Type-checking (TF-829).
- Serialization (TF-837).
- Move `DifferentiableAttr` definition above `DeclAttributes` in
include/swift/AST/Attr.h, like other attributes.
- Remove unnecessary arguments from `DifferentiableAttr::DifferentiableAttr`
and `DifferentiableAttr::setDerivativeGenericSignature`.
- Add libSyntax test for `@differentiable` attributes.
