`participatesInInference` is now always true for
a non-empty body, remove it along with the separate
type-checking logic such that empty bodies are
type-checked together with the context.
Although I don't plan to bring over new assertions wholesale
into the current qualification branch, it's entirely possible
that various minor changes in main will use the new assertions;
having this basic support in the release branch will simplify that.
(This is why I'm adding the includes as a separate pass from
rewriting the individual assertions)
If closure appears inside of a pack expansion, the elements
that reference pack elements have to bring expansion's shape
type in scope to make sure that the shapes match.
Track the implied result exprs in the constraint
system, and allow arbitrary propagation of
implied results down if/switch expression
branches. This is required for allowing implied
results in non-single-expression closures.
Currently we don't insert an intermediate
`SyntacticElement` locator element for the `if`
statement in a SingleValueStmtExpr, which leads
to an assertion failure when attempting to simplify
a following `TernaryBranch` element.
Move the insertion of the `SyntacticElement` locator
element for the statement into the
SingleValueStmtExpr constraint generation function,
and remove it from the statement visitors themselves.
For the other cases, the `SyntacticElement` was
already being inserted for children of a BraceStmt,
so we were actually previously ending up with
duplicated elements in a couple of places.
Unify the implementation between single-expression
and multi-statement closures. Because we're now
storing a contextual type for single expression
closure returns, update a code completion test to
bring its behavior inline with the multi-statement
case.
This wasn't consistently used, and consequently
could result in some expressions getting their
parents invalidated. Instead, replace it with a
query to make sure we don't try and add an
expression we've already computed the parent info
for.
This models the conversion from an uninhabited
value to any type, and allows us to get rid of
a couple of places where we'd attempt to drop
the return statement instead.
Remove this bit from function decls and closures.
Instead, for closures, infer it from the presence
of a single return or single expression AST node
in the body, which ought to be equivalent, and
automatically takes result builders into
consideration. We can also completely drop this
query from AbstractFunctionDecl, replacing it
instead with a bit on ReturnStmt.
Most clients only want to set one of the two
parameters, split it into `setPattern` and
`setInitContext` (the latter of which now
handles calling `setBinding`).
Use the PatternBindingInitializer context if we
have one. This also uncovered a parser issue where
we would mistakenly create a
PatternBindingInitializer in top-level code after
parsing the initializers.
Start classifying all potential throw sites within a constraint
system and associate them with the nearest enclosing catch node. Then,
determine the thrown error type for a given catch node by taking the
union of the thrown errors at each potential throw site. Use this to
compute the error type thrown from the body of a `do..catch` block
within a closure.
This behavior is limited to the upcoming feature `FullTypedThrows`.
Correctly determining the DeclContext needed for an
ExplicitCaughtTypeRequest is tricky for a number of callers, and
mistakes here can easily lead to redundant computation of the caught
type, redundant diagnostics, etc.
Instead, put a `DeclContext` into `DoCatchStmt`, because that's the
only catch node that needs a `DeclContext` but does not have one.
Teach the constraint system to use the same primitives as elsewhere to
determine the type context for a `throw` statement and the caught
error type within a `do..catch` statement. This makes
explicitly-specified `throws` work on `do..catch` that occurs in
closures.
Cleans up some redundant computations for caught error types.
These two requests are effectively doing the same thing to two
different cases within CatchNode. Unify the requests into a single
request, ExplicitCaughtTypeRequest, which operates on a CatchNode.
This also moves the logic for closures with explicitly-specified throws
clauses into the same request, taking it out of the constraint system.
Doing so fits better into conjunction model which leads to more
granular control over what variables are brought into scope during
`where` clause expression checking.
These changes also remove "one-way bind" flag from "for-in" statement
target.
