Instead of assuming that `if let <expr>` is meant
to be `if case <expr> = ...`, turn it into
`if let _ = <expr>`, which is consistent with
the fix-it we suggest.
This currently doesn't have much of an effect on
the diagnostics we produce, but will be important
once we start doing bidirectional inference for
ExprPatterns, as it avoids unhelpful diagnostics.
When recovering from a parser error in an expression, we resumed parsing at a '{'. I assume this was because we wanted to continue inside e.g. an if-body if parsing the condition failed, but it's actually causing more issue because when parsing e.g.
```swift
expr + has - error +
functionTakesClosure {
}
```
we continue parsing at the `{` of the trailing closure, which is a completely garbage location to continue parsing.
The motivating example for this change was (in a result builder)
```swift
Text("\(island.#^COMPLETE^#)")
takeTrailingClosure {}
```
Here `Text(…)` has an error (because it contains a code completion token) and thus we skip `takeTrailingClosure`, effectively parsing
```swift
Text(….) {}
```
which the type checker wasn’t very happy with and thus refused to provide code completion. With this change, we completely drop `takeTrailingClosure {}`. The type checker is a lot happier with that.
We have two similar code paths here that should probably be unified. For
now, make sure the more-specific one for pattern matching kicks in first.
Fixes rdar://problem/59838566.
Generate a complete set of constraints for EnumElement patterns, e.g.,
case let .something(x, y)
Most of the complication here comes from the implicit injection of optionals,
e.g., this case can be matched to an optional of the enum type of which
`something` is a member. To effect this change, introduce a locator for
pattern matching and use it to permit implicit unwrapping during member
lookup without triggering an error.
Note also labels are dropped completely when performing the match,
because labels can be added or removed when pattern matching. Label
conflict are currently diagnosed as part of coercePatternToType, which
suffices so long as overloading cases based on argument labels is not
permitted.
The primary observable change from this commit is in diagnostics: rather
than diagnostics being triggered by `TypeChecker::coercePatternToType`,
diagnostics for matching failures here go through the diagnostics machinery
of the constraint solver. This is currently a regression, because
there are no custom diagnostics for pattern match failures within the
constraint system. This regression will be addressed in a subsequent
commit; for now, leave those tests failing.
Patch up all the places that are making a syntactic judgement about the
isInvalid() bit in a ValueDecl. They may continue to use that query,
but most guard themselves on whether the interface type has been set.
This is an amalgam of simplifications to the way VarDecls are checked
and assigned interface types.
First, remove TypeCheckPattern's ability to assign the interface and
contextual types for a given var decl. Instead, replace it with the
notion of a "naming pattern". This is the pattern that semantically
binds a given VarDecl into scope, and whose type will be used to compute
the interface type. Note that not all VarDecls have a naming pattern
because they may not be canonical.
Second, remove VarDecl's separate contextual type member, and force the
contextual type to be computed the way it always was: by mapping the
interface type into the parent decl context.
Third, introduce a catch-all diagnostic to properly handle the change in
the way that circularity checking occurs. This is also motivated by
TypeCheckPattern not being principled about which parts of the AST it
chooses to invalidate, especially the parent pattern and naming patterns
for a given VarDecl. Once VarDecls are invalidated along with their
parent patterns, a large amount of this diagnostic churn can disappear.
Unfortunately, if this isn't here, we will fail to catch a number of
obviously circular cases and fail to emit a diagnostic.
the item list if we find it. (While still erroring that we expected a brace on the first bad token.) Improves recovery in general and in SR-5943 in particular.
pattern matches. In the case of an 'if let' with an explicit type, produce a
Taylor'd diagnostic that rewrites the condition to the right type.
This wraps up:
<rdar://problem/27457457> [Type checker] Diagnose unsavory optional injections
This reverts commit dc24c2bd34.
Turns out Chris fixed the build but when I was looking at the bots, his fix had
not been tested yet, so I thought the tree was still red and was trying to
revert to green.
In the condition expressions of if, while and guard statements we were
throwing away the AST if there was a parse error in the condition, or
the brace statement was missing. This led to poor code-completion for
unresolved members (enums, options sets) because we couldn't find the
parent expression to type-check.
There are a few minor diagnostic changes because we now do more
type-checking of these conditions, particularly if they end up
containing an unused closure.
SR-2001
Make the following patterns illegal:
if var x = ... {
...
}
guard var x = ... else {
...
}
while var x = ... {
...
}
And provide a replacement fixit 'var' -> 'let'.
rdar://problem/23172698
Swift SVN r32855
These names don't go into scope until after they've been bound. Not having
this broke "if let foo = foo" for shadowing-based unwrapping.
rdar://problem/21961391
Swift SVN r30539
Enhance fixItRemove() to be a bit more careful about what whitespace it leaves around: if the thing it is removing has leading and trailing whitespace already, this nukes an extra space to avoid leaving double spaces or incorrectly indented results.
This includes an extra fix for looking off the start of a buffer, which extractText doesn't and can't handle.
This fixes <rdar://problem/21045509> Fixit deletes 'let' from non-binding 'if case let' statements, but leaves an extra space
Swift SVN r29449
if the thing it is removing has leading and trailing whitespace already, this nukes
an extra space to avoid leaving double spaces or incorrectly indented results. This
fixes <rdar://problem/21045509> Fixit deletes 'let' from non-binding 'if case let' statements, but leaves an extra space
Swift SVN r29419
that make vardecls and subscripts immutable. This makes the indirect cases
a lot more specific ("this is a get-only property" instead of "this is
immutable") and allows us to consolidate a bunch of code:
2 files changed, 45 insertions(+), 119 deletions(-)
Swift SVN r28954
resolution. This allows us to produce better QoI and simplifies code. This would
be a lot simpler if not for our weird representation of clang enum aliases. :-(
Swift SVN r28760
var/let bindings to _ when they are never used, and use some values that
are only written. This is a testsuite cleanup, NFC. More to come.
Swift SVN r28406
