Parse 'var [behavior] x: T', and when we see it, try to instantiate the property's
implementation in terms of the given behavior. To start out, behaviors are modeled
as protocols. If the protocol follows this pattern:
```
protocol behavior {
associatedtype Value
}
extension behavior {
var value: Value { ... }
}
```
then the property is instantiated by forming a conformance to `behavior` where
`Self` is bound to the enclosing type and `Value` is bound to the property's
declared type, and invoking the accessors of the `value` implementation:
```
struct Foo {
var [behavior] foo: Int
}
/* behaves like */
extension Foo: private behavior {
@implements(behavior.Value)
private typealias `[behavior].Value` = Int
var foo: Int {
get { return value }
set { value = newValue }
}
}
```
If the protocol requires a `storage` member, and provides an `initStorage` method
to provide an initial value to the storage:
```
protocol storageBehavior {
associatedtype Value
var storage: Something<Value> { ... }
}
extension storageBehavior {
var value: Value { ... }
static func initStorage() -> Something<Value> { ... }
}
```
then a stored property of the appropriate type is instantiated to witness the
requirement, using `initStorage` to initialize:
```
struct Foo {
var [storageBehavior] foo: Int
}
/* behaves like */
extension Foo: private storageBehavior {
@implements(storageBehavior.Value)
private typealias `[storageBehavior].Value` = Int
@implements(storageBehavior.storage)
private var `[storageBehavior].storage`: Something<Int> = initStorage()
var foo: Int {
get { return value }
set { value = newValue }
}
}
```
In either case, the `value` and `storage` properties should support any combination
of get-only/settable and mutating/nonmutating modifiers. The instantiated property
follows the settability and mutating-ness of the `value` implementation. The
protocol can also impose requirements on the `Self` and `Value` types.
Bells and whistles such as initializer expressions, accessors,
out-of-line initialization, etc. are not implemented. Additionally, behaviors
that instantiate storage are currently only supported on instance properties.
This also hasn't been tested past sema yet; SIL and IRGen will likely expose
additional issues.
My previous commit here didn’t work correctly for nested tuples, both
because it didn’t recurse into them to propagate access kind correctly
and because an outer TupleIndex overload (when indexing into the nested
tuple) could still be expecting an lvalue type.
This fix is much better. ConstraintSystem::resolveOverload now
correctly always expects rvalue types from rvalue tuples. And during
applyMemberRefExpr, if the overload expects an rvalue but the tuple
contains lvalues, coerceToType() correctly does any recursive munging
of the tuple expr required.
The issue here is that the constraint solver was deciding on
FixKind::RelabelCallTuple as the fix for the problem and emitting the
diagnostic, even though there were two different fixes possible.
CSDiags has the infrastructure to support doing doing the right thing
here, but is only being used for ApplyExprs, not SubscriptExprs.
The solution is to fix both problems: remove FixKind::RelabelCallTuple,
to let CSDiags handle the problem, and enhance CSDiags to treat
SubscriptExpr more commonly with ApplyExpr. This improves several cases
where the solver was picking one solution randomly and suggesting that
as a fix, instead of listing that there are multiple different solutions.
Now that we have expressions that start with #, the [# introducer for
object literals is no longer guaranteed to indicate an object
literal. For example:
[#line, #column]
is an array literal and
[#line : #column]
is a dictionary literal. Use additional lookahead in the parser to
disambiguate these cases from object literals. Fixes
rdar://problem/24533081.
In SR-628 in particular, the problem was an assert that an AccessKind
was being set on a non-lvalue, but there were lots of asserts here in
various scenarios, the most common other ones being an AccessKind not
being set assertion by the ASTVerifier or lvalue-ness not matching
between tuple expr and tuple element expr.
This checks for lvalues in the tuple when a tuple indexing expr is built,
and if there are any, inserts load exprs into the lvalue elements to make all rvalues.
Introduce Fix-Its to aid migration from selectors spelled as string
literals ("foo:bar:", which is deprecated), as well as from
construction of Selector instances from string literals
(Selector("foo:bar"), which is still acceptable but not recommended),
to the #selector syntax. Jump through some hoops to disambiguate
method references if there are overloads:
fixits.swift:51:7: warning: use of string literal for Objective-C
selectors is deprecated; use '#selector' instead
_ = "overloadedWithInt:" as Selector
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#selector(Bar.overloaded(_:) as (Bar) -> (Int) -> ())
In the cases where we cannot provide a Fix-It to a #selector
expression, we wrap the string literal in a Selector(...) construction
to suppress the deprecation warning. These are also easily searchable
in the code base.
This also means we're doing more validation of the string literals
that go into Selector, i.e., that they are well-formed selectors and
that we know about some method that is @objc and has that
selector. We'll warn if either is untrue.
This pull request broke the following tests on several build configurations
(eg --preset=buildbot,tools=RA,stdlib=DA)
1_stdlib/Reflection.swift
1_stdlib/ReflectionHashing.swift
1_stdlib/UnsafePointer.swift.gyb
This reverts commit c223a3bf06, reversing
changes made to 5c2bb09b09.
Changes:
- Reverted commit reverting original SR-88 commit
- Removed mirror children helper collections and related code
- Rewrote some tests to keep them working properly
- Wrote two more tests for the three pointer APIs to ensure no crashes if created using a value > Int64.max
This reverts commit 8917eb0e5a.
Fix <rdar://problem/16812341> QoI: Poor error message when providing a default value for a subscript parameter
by emitting a more specific diagnostic about the cases that aren't allowed.
- Improve the specific cases of nil and empty collection literals.
- Improve cases of contextual member lookup where the result type of the looked up member disagrees with context.
- Add some fixme's to the testsuite for cases of this diagnostic that should be diagnosed in other ways.
This standardizes processing of callees in invalid applyexprs, eliminating
bogus diagnostics like:
t.swift:6:2: error: cannot invoke closure of type '() -> _' with an argument list of type '()'
we now properly diagnose the example in closure/closures.swift as ambiguous,
but don't do a particularly good job of saying why. That is to follow.
Jira: SR-88
Changes:
- Removed stdlib type conformances to _Reflectable
- Conformed stdlib types to CustomReflectable, CustomPlaygroundQuickLookable
- Rewrote dump() function to not use _reflect()
- CGRect, CGPoint, CGSize now conform to CustomDebugStringConvertible
- Rewrote unit tests for compatibility with new API
Basic implementatation of SE-0021, naming functions with argument
labels. Handle parsing of compound function names in various
unqualified-identifier productions, updating the AST representation of
various expressions from Identifiers to DeclNames. The result doesn't
capture all of the source locations we want; more on that later.
As part of this, remove the parsing code for the "selector-style"
method names, since we now have a replacement. The feature was never
publicized and doesn't make sense in Swift, so zap it outright.
Type resolution wasn't looking through property initializer decl contexts
to find out whether an unbound generic type reference was referring to the
enclosing type. Previously we'd reject this with:
error: cannot convert value of type 'Int' to specified type 'Int'
private var data: Int = Matrix4.size()
~~~~~~~~^~~~~~
which was super confusing. The problem was that we weren't resolving
Matrix4 to Matrix4<T>.
ASTPrinter of type variables was trying to dig an original type out of the
locator and archetype that opened the type variable in the first place. This
was prone to failure and never helped, so just always print type vars as _.
The affected diagnostics always come out better and this saves a word of storage
for each type variable.
a constraint system in "allowFreeTypeVariables" mode. Previously, we
only allowed a few specific constraints, now we allow any relational and
member constraints. The later one is a big deal because it means that we
can allow ".Foo" expressions as ambiguous solutions, which CSDiags can
handle well.
This unblocks solving 23942743 and enables some minor improvements across
the board, including diagnosing things like this better:
Optional(.none) // now: generic parameter 'T' could not be inferred
That said, it also just permutes some non-awesome diagnostics.
