Right now we use TupleShuffleExpr for two completely different things:
- Tuple conversions, where elements can be re-ordered and labels can be
introduced/eliminated
- Complex argument lists, involving default arguments or varargs
The first case does not allow default arguments or varargs, and the
second case does not allow re-ordering or introduction/elimination
of labels. Furthermore, the first case has a representation limitation
that prevents us from expressing tuple conversions that change the
type of tuple elements.
For all these reasons, it is better if we use two separate Expr kinds
for these purposes. For now, just make an identical copy of
TupleShuffleExpr and call it ArgumentShuffleExpr. In CSApply, use
ArgumentShuffleExpr when forming the arguments to a call, and keep
using TupleShuffleExpr for tuple conversions. Each usage of
TupleShuffleExpr has been audited to see if it should instead look at
ArgumentShuffleExpr.
In sequent commits I plan on redesigning TupleShuffleExpr to correctly
represent all tuple conversions without any unnecessary baggage.
Longer term, we actually want to change the representation of CallExpr
to directly store an argument list; then instead of a single child
expression that must be a ParenExpr, TupleExpr or ArgumentShuffleExpr,
all CallExprs will have a uniform representation and ArgumentShuffleExpr
will go away altogether. This should reduce memory usage and radically
simplify parts of SILGen.
Ensure that we get the correct behaviour when we are not in the
single-expression case, and remove code that handled 0-element bodies,
which is no longer needed after the parser change.
When completing in the only expression of closure, use the return type
of the closure as the type context for the code-completion. However,
since code-completion may be on an incomplete input, we only use the
return type to improve the quality of the result, not to mark it
invalid, since (a) we may add another statement afterwards, or (b) if
the context type is Void it doesn't need to match the value.
To return accurate type of the expression.
i.e.
MyType.foo(#^COMPLETE^# // -> (MyType) -> (args...) -> Result
MyType().foo(#^COMPLETE^# // -> (args...) -> Result
Instead of re-typechecking parsed expression, find typechecked
expression that corresponds to the parsed expression from the
typechecked decl context, because the sub expressions of the parsed
expression can be weirdly mutated/replaced by decl context typechecking.
rdar://problem/48141174
For `Initializer` decl context, type context analyzer should look into
its parent context because that might constrain initializer's type.
rdar://problem/48208253
`source.request.conformingmethods` is a new SourceKit request which
receives a source position and a list of protocol namses, returns a list
of methods whose return type conforms to the requested protocols.
rdar://problem/44699573
