- Enable 'catch is NSError' and 'catch let e as NSError {' patterns to
a) work, and b) be considered to be exhaustive catches. This enables
people to catch an error and *use* it as an NSError directly, instead
of having to do boiler-platey cases. This is particularly important
for the migrator.
- Do not warn about non-noop coersion casts (like "_ as NSError" when
matching an ErrorType), since they provide useful type adjustment to
the subpattern. Still warn on noop ones.
- Simplify CatchStmt::isSyntacticallyExhaustive to use
Pattern::isRefutablePattern. Add a FIXME, because the parser is guiding
closure "throws" inference before the pattern is type checked, which means
that it is incorrect (but only in subtle cases).
- When diagnosing pointless 'as' patterns like:
switch 4 {
case _ as Int: break
say "'as' test is always true" instead of "'is' test is always true".
Swift SVN r28774
Factor out the special case condition for deciding whether a period_prefix should be treated like a MemberRef postfix production instead of a new UnresolvedMemberExpr, and share it with the generic type disambiguation code, so that 'Foo<T>\n.bar()' parses consistently with 'Foo\n.bar()'. Extend the condition to consider a '.foo' reference on a line by itself in postfix position as a postfix continuation as well, allowing properties to be chained in builder fashion too. Addresses rdar://problem/20238557, but we may want to still make a more general change to the grammar here.
Swift SVN r28707
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
Now we bind the defer body into a ClosureExpr and emit it at the point of
the defer. At any exit points out of the controlled region, we emit a call
to the closure.
This should cover any problems where expressions cannot be emitted multiple times.
However, this is dramatically more complex than the obvious implementation, so I
hope this patch can be reverted.
Swift SVN r27767
(somewhat ironically, given that we added it for throw) because we model
throw as an Expr currently which makes it more difficult in Sema. SILGen
catches this situation and any others that I didn't remember to handle here.
Swift SVN r27762
The rule changes are as follows:
* All functions (introduced with the 'func' keyword) have argument
labels for arguments beyond the first, by default. Methods are no
longer special in this regard.
* The presence of a default argument no longer implies an argument
label.
The actual changes to the parser and printer are fairly simple; the
rest of the noise is updating the standard library, overlays, tests,
etc.
With the standard library, this change is intended to be API neutral:
I've added/removed #'s and _'s as appropriate to keep the user
interface the same. If we want to separately consider using argument
labels for more free functions now that the defaults in the language
have shifted, we can tackle that separately.
Fixes rdar://problem/17218256.
Swift SVN r27704
Change all uses of "do { ... } while <cond>" to use "repeat" instead.
Rename DoWhileStmt to RepeatWhileStmt. Add diagnostic suggesting change
of 'do' to 'repeat' if a condition is found afterwards.
<rdar://problem/20336424> rename do/while loops to repeat/while & introduce "repeat <count> {}" loops
Swift SVN r27650
Now that tuple pattern labels are squared away, we can detect mismatches and produce
diagnostics that point exactly to the problematic label. Right now we require the
tuple labels to match up (or be absent) from the pattern, and produce this diagnostic
if not:
x.swift:7:20: error: tuple pattern element label 'xxx' must be 'one'
case let .Case(xxx: _, two: x):
^
In the future we could support reshuffling if it someone cares enough to support it.
The important thing for now is to fix the miscompilation.
Swift SVN r26865
and refutable pattern bindings without an initializer.
- Enhance ASTDumper to dump where/else clauses on PBDs.
- Merge if/let conditional PBD logic into the mainline logic now that they are all
potentially conditional (more simplifications coming for this)
add tests for the fixits, which exercise the earlier SourceRange enhancments, e.g.:
x.swift:3:5: error: refutable pattern match can fail; add an else {} to handle this condition
let o? = a
^~
else {}
Swift SVN r26751
- Enhance PBD with a whereExpr/elseStmt field to hold this.
- Start parsing the pattern of let/var decls as a potentially refutable pattern. It becomes
a semantic error to use a refutable pattern without an 'else' (diagnostics not in place yet).
- Change validatePatternBindingDecl to use 'defer' instead of a goto to ensure cleanups on exit.
- Have it resolve the pattern in a PBD, rewriting it from expressions into pattern nodes when valid.
- Teach resolvePattern to handle TypedPatterns now that they can appear (wrapping) refutable patterns.
- Teach resolvePattern to handle refutable patterns in PBD's without initializers by emitting a diagnostic
instead of by barfing, fixing regressions on validation tests my previous patch caused, and fixing
two existing validation test crashers.
Sema, silgen, and more tests coming later.
Swift SVN r26706
For now, we assume that 'while' after the braces starts
a do/while rather than being an independent statement.
We should disambiguate this, or better, remove do/while.
Tests later.
Swift SVN r26079
In an existential context, allow 'case Enum.Case:' by implicitly introducing a cast pattern, treating it as 'case Enum.Case as Enum:'. This will be important for the error handling design, where we want ErrorType-conforming enums to be pattern-matchable out of an ErrorType existential using 'catch' patterns.
Swift SVN r25968
This doesn't allow 'continue' out of an if statement for the same reason we don't
allow it on switch: we'd prefer people to write loops more explicitly.
Swift SVN r25565
Most tests were using %swift or similar substitutions, which did not
include the target triple and SDK. The driver was defaulting to the
host OS. Thus, we could not run the tests when the standard library was
not built for OS X.
Swift SVN r24504
These changes make the following improvements to how we generate diagnostics for expression typecheck failure:
- Customizing a diagnostic for a specific expression kind is as easy as adding a new method to the FailureDiagnosis class,
and does not require intimate knowledge of the constraint solver’s inner workings.
- As part of this patch, I’ve introduced specialized diagnostics for call, binop, unop, subscript, assignment and inout
expressions, but we can go pretty far with this.
- This also opens up the possibility to customize diagnostics not just for the expression kind, but for the specific types
involved as well.
- For the purpose of presenting accurate type info, partially-specialized subexpressions are individually re-typechecked
free of any contextual types. This allows us to:
- Properly surface subexpression errors.
- Almost completely avoid any type variables in our diagnostics. In cases where they could not be eliminated, we now
substitute in "_".
- More accurately indicate the sources of errors.
- We do a much better job of diagnosing disjunction failures. (So no more nonsensical ‘UInt8’ error messages.)
- We now present reasonable error messages for overload resolution failures, informing the user of partially-matching
parameter lists when possible.
At the very least, these changes address the following bugs:
<rdar://problem/15863738> More information needed in type-checking error messages
<rdar://problem/16306600> QoI: passing a 'let' value as an inout results in an unfriendly diagnostic
<rdar://problem/16449805> Wrong error for struct-to-protocol downcast
<rdar://problem/16699932> improve type checker diagnostic when passing Double to function taking a Float
<rdar://problem/16707914> fatal error: Can't unwrap Optional.None…Optional.swift, line 75 running Master-Detail Swift app built from template
<rdar://problem/16785829> Inout parameter fixit
<rdar://problem/16900438> We shouldn't leak the internal type placeholder
<rdar://problem/16909379> confusing type check diagnostics
<rdar://problem/16951521> Extra arguments to functions result in an unhelpful error
<rdar://problem/16971025> Two Terrible Diagnostics
<rdar://problem/17007804> $T2 in compiler error string
<rdar://problem/17027483> Terrible diagnostic
<rdar://problem/17083239> Mysterious error using find() with Foundation types
<rdar://problem/17149771> Diagnostic for closure with no inferred return value leaks type variables
<rdar://problem/17212371> Swift poorly-worded error message when overload resolution fails on return type
<rdar://problem/17236976> QoI: Swift error for incorrectly typed parameter is confusing/misleading
<rdar://problem/17304200> Wrong error for non-self-conforming protocols
<rdar://problem/17321369> better error message for inout protocols
<rdar://problem/17539380> Swift error seems wrong
<rdar://problem/17559593> Bogus locationless "treating a forced downcast to 'NSData' as optional will never produce 'nil'" warning
<rdar://problem/17567973> 32-bit error message is really far from the mark: error: missing argument for parameter 'withFont' in call
<rdar://problem/17671058> Wrong error message: "Missing argument for parameter 'completion' in call"
<rdar://problem/17704609> Float is not convertible to UInt8
<rdar://problem/17705424> Poor error reporting for passing Doubles to NSColor: extra argument 'red' in call
<rdar://problem/17743603> Swift compiler gives misleading error message in "NSLayoutConstraint.constraintsWithVisualFormat("x", options: 123, metrics: nil, views: views)"
<rdar://problem/17784167> application of operator to generic type results in odd diagnostic
<rdar://problem/17801696> Awful diagnostic trying to construct an Int when .Int is around
<rdar://problem/17863882> cannot convert the expression's type '()' to type 'Seq'
<rdar://problem/17865869> "has different argument names" diagnostic when parameter defaulted-ness differs
<rdar://problem/17937593> Unclear error message for empty array literal without type context
<rdar://problem/17943023> QoI: compiler displays wrong error when a float is provided to a Int16 parameter in init method
<rdar://problem/17951148> Improve error messages for expressions inside if statements by pre-evaluating outside the 'if'
<rdar://problem/18057815> Unhelpful Swift error message
<rdar://problem/18077468> Incorrect argument label for insertSubview(...)
<rdar://problem/18079213> 'T1' is not identical to 'T2' lacks directionality
<rdar://problem/18086470> Confusing Swift error message: error: 'T' is not convertible to 'MirrorDisposition'
<rdar://problem/18098995> QoI: Unhelpful compiler error when leaving off an & on an inout parameter
<rdar://problem/18104379> Terrible error message
<rdar://problem/18121897> unexpected low-level error on assignment to immutable value through array writeback
<rdar://problem/18123596> unexpected error on self. capture inside class method
<rdar://problem/18152074> QoI: Improve diagnostic for type mismatch in dictionary subscripting
<rdar://problem/18242160> There could be a better error message when using [] instead of [:]
<rdar://problem/18242812> 6A1021a : Type variable leaked
<rdar://problem/18331819> Unclear error message when trying to set an element of an array constant (Swift)
<rdar://problem/18414834> Bad diagnostics example
<rdar://problem/18422468> Calculation of constant value yields unexplainable error
<rdar://problem/18427217> Misleading error message makes debugging difficult
<rdar://problem/18439742> Misleading error: "cannot invoke" mentions completely unrelated types as arguments
<rdar://problem/18535804> Wrong compiler error from swift compiler
<rdar://problem/18567914> Xcode 6.1. GM, Swift, assignment from Int64 to NSNumber. Warning shown as problem with UInt8
<rdar://problem/18784027> Negating Int? Yields Float
<rdar://problem/17691565> attempt to modify a 'let' variable with ++ results in typecheck error about @lvalue Float
<rdar://problem/17164001> "++" on let value could give a better error message
Swift SVN r23782
Start capitalizing on some of the new diagnostic machinery in a few different ways:
- When mining constraints for type information, utilize constraints "favored" by the overload resolution process.
- When printing type variables, if the variable was created by opening a literal expression, utilize the literal
default type or conformance if possible.
- Utilize syntactic information when crafting diagnostics:
- If the constraint miner can produce a better diagnostic than the recorded failure, diagnose via constraints.
- Factor in the expression kind when choosing which types to include in a diagnostic message.
- Start customizing diagnostics based on the amount of type data available.
What does all this mean?
- Fewer type variables leaking into diagnostic messages.
- Far better diagnostics for overload resolution failures. Specifically, we now print proper argument type data
for failed function calls.
- No more "'Foo' is not convertible to 'Foo'" error messages
- A greater emphasis on type data means less dependence on the ordering of failed constraints. This means fewer
inscrutable diagnostics complaining about 'UInt8' when all the constituent expressions are of type Float.
So we still have a ways to go, but these changes should greatly improve the number of head-scratchers served up
by the type checker.
These changes address the following radars:
rdar://problem/17618403
rdar://problem/17559042
rdar://problem/17007456
rdar://problem/17559042
rdar://problem/17590992
rdar://problem/17646988
rdar://problem/16979859
rdar://problem/16922560
rdar://problem/17144902
rdar://problem/16616948
rdar://problem/16756363
rdar://problem/16338509
Swift SVN r20927
Mechanically add "Type" to the end of any protocol names that don't end
in "Type," "ible," or "able." Also, drop "Type" from the end of any
associated type names, except for those of the *LiteralConvertible
protocols.
There are obvious improvements to make in some of these names, which can
be handled with separate commits.
Fixes <rdar://problem/17165920> Protocols `Integer` etc should get
uglier names.
Swift SVN r19883
We haven't been advertising this syntax much, and it's closure form
was completely broken anyway, so don't jump through hoops to provide
great Fix-Its here.
Swift SVN r19277
We enable pattern matching against nil even if the T of an option type isn't comparable by implementing
a crazy new ~= operator. This approach would work to enable comparisons against nil as well, but I can't
make it happen without introducing ambiguities.
Swift SVN r18919
I didn't want to rip this logic out wholesale. There is a possibility
the character lexing can be reborn/revisited later, and
disabling it in the parser was easy.
Swift SVN r18102
There's a lot more work to do here, but start to categorize tests
along the lines of what a specification might look like, with
directories (chapters) for basic concepts, declarations, expressions,
statements, etc.
Swift SVN r9958
