In preparation for the switch to llvm::Optional, which doesn't have this.
I suggested it, but got some pushback from David Blaikie, which is
understandable because implicit conversions are dangerous.
std::experimental::optional also doesn't have this, and we don't use it
too much. The only cost is being slightly more explicit when relying on
conversions to give us a T to then wrap in an Optional.
Swift SVN r22472
This patch adds the ability (-enable-experimental-unavailable-as-optional) to
treat potentially unavailable declarations as if they had optional types. For
the moment, this is only implemented for global variables.
The high-level approach is to (1) record the potential unavailability of a
declaration reference in the overload choice during constraint generation; (2)
treat the declaration as if it had an optional type during overload resolution
(this is similar to how optional protocol members are treated); and (3) add an
implicit conversion (UnavailableToOptionalExpr) during constraint application
to represent the run-time availability check and optional injection.
This patch does not implement SILGen for UnavailableToOptionalExpr.
Swift SVN r22245
This change includes a number of simplifications that allow us to
eliminate the type checker hack that specifically tries
AssertString. Doing so provides a 25% speedup in the
test/stdlib/ArrayNew.swift test (which is type-checker bound).
The specific simplifications here:
- User-level
assert/precondition/preconditionalFailure/assertionFailer/fatalError
always take an autoclosure producing a String, eliminating the need
for the StaticString/AssertString dance.
- Standard-library internal _precondition/_sanityCheck/etc. always
take a StaticString. When we want to improve the diagnostics in the
standard library, we can provide a separate overload or
differently-named function.
- Remove AssertString, AssertStringType, StaticStringType, which are
no longer used or needed
- Remove the AssertString hack from the compiler
- Remove the "BooleanType" overloads of these functions, because
their usefuless left when we stopped making optional types conform
to BooleanType (sorry, should have been a separate patch).
Swift SVN r22139
When the solver has attempted to produce a solution using the default
literal type tha has failed, dont' try every type that conforms to
that literal type. Instead, try the bridged class type (which deals
with the common AnyObject case) or one of two other options:
- For integer literals, try the default floating point type (Double)
- For string literals, try the standard library's AssertString (this
is a temporary hack)
This limits exponential blow-up in cases where the literal's type
cannot be determined from context. Addresses rdar://problem/18307267.
Swift SVN r22131
Locators that refer to opened type parameters now carry information
about the source location where we needed to open the type, so that
(for example) we can trace an opened type parameter back to the
location it was opened. As part of this, eliminate the "rootExpr"
fallback, because we're threading constraint locators everywhere.
This is infrastructural, and should be NFC.
Swift SVN r21919
This allows UnicodeScalars to be constructed from an integer, rather
then from a string. Not only this avoids an unnecessary memory
allocation (!) when creating a UnicodeScalar, this also allows the
compiler to statically check that the string contains a single scalar
value (in the same way the compiler checks that Character contains only
a single extended grapheme cluster).
rdar://17966622
Swift SVN r21198
Expose Substitution's archetype, replacement, and conformances only through getters so we can actually assert invariants about them. To start, require replacement types to be materializable in order to catch cases where the type-checker tries to bind type variables to lvalue or inout types, and require the conformance array to match the number of protocol conformances required by the archetype. This exposes some latent bugs in the test suite I've marked as failures for now:
- test/Constraints/overload.swift was quietly suffering from <rdar://problem/17507421>, but we didn't notice because we never tried to codegen it.
- test/SIL/Parser/array_roundtrip.swift doesn't correctly roundtrip substitutions, which I filed as <rdar://problem/17781140>.
Swift SVN r20418
Introduce the new BooleanLiteralConvertible protocol for Boolean
literals. Take "true" and "false" as real keywords (which is most of the
reason for the testsuite churn). Make Bool BooleanLiteralConvertible
and the default Boolean literal type, and ObjCBool
BooleanLiteralConvertible. Fixes <rdar://problem/17405310> and the
recent regression that made ObjCBool not work with true/false.
Swift SVN r19728
These methods all act on the desugared type, so the result would always be
false/null.
Also removes a few mistaken uses of getAs caught by this change.
Swift SVN r19585
When we see a '.member' expression in optional context, look for the member in the optional's object type if it isn't found in Optional itself. <rdar://problem/16125392>
Swift SVN r19469
not a struct wrapping an Optional.
Among other things, this means you can now pattern-match on
an IUO. It also makes it more convenient to build and destroy
them.
SILGen's type lowering should probably canonicalize one kind
of optional to the other so that we don't get silly abstraction
costs from conversion.
Swift SVN r18991
This makes categories of NSString, NSArray, and NSDictionary available
on String, Array, and Dictionary. Note that we only consider
categories not present in the Objective-C Foundation module, because
we want to manually map those APIs ourselves. Hence, no changes to the
NSStringAPI. Implements <rdar://problem/13653329>.
Swift SVN r18920
This is all goodness, and eliminates a major source of implicit conversions.
One thing this regresses on though, is that we now reject "x == nil" where
x is an option type and the element of the optional is not Equtatable. If
this is important, there are ways to enable this, but directly testing it as
a logic value is more straight-forward.
This does not include support for pattern matching against nil, that will be
a follow on patch.
Swift SVN r18918
Semantically, these expressions handle the same thing: an upcast of a
collection when the underlying element types of the source are
subtypes of or can be bridged to subtypes of the destination. This
reduces some branching in the type checker and eliminates duplication
in SILGen.
Swift SVN r18865
One difficulty in generating reasonable diagnostic data for type check failures has been the fact that many constraints had been synthesized without regard for where they were rooted in the program source. The result of this was that even though we would store failure information for specific constraints, we wouldn't emit it for lack of a source location. By making location data a non-optional component of constraints, we can begin diagnosing type check errors closer to their point of failure.
Swift SVN r18751
- Continue adding support for checked downcasts of array types (rdar://problem/16535104)
- Fix non-bridged array conversions post-r17868
- Fix rdar://problem/16773693
- Add tests for NSArray coercions to and from Array<T>
Swift SVN r17957
This is fairly ugly, because we're halfway between a-function-type-takes-a-tuple and a-function-type-takes-a-set-of-parameters. However, it's another step toward -strict-keyword-arguments.
Swift SVN r17727
of T[]() instead of Array<T>().
I didn't do this in the guts of Array.swift because the abstraction
is harmful in the implementation of Array itself.
NFC.
Swift SVN r17683
Introduce a model where an argument name is a keyword argument if:
- It is an argument to an initializer, or
- It is an argument to a method after the first argument, or
- It is preceded by a back-tick (`), or
- Both a keyword argument name and an internal parameter name are
specified.
Provide diagnostics Fix-Its to clean up cases where the user is
probably confused, i.e.,
- "_ x: Int" -> "x: Int" where "x" would not have been a keyword
argument anyway
- "x x: Int" -> "`x: Int"
This covers the compiler side of <rdar://problem/16741975> and
<rdar://problem/16742001>.
Update the AST printer to print in this form, never printing just
a type for a parameter name because we're also going to adopt
<rdar://problem/16737312> and it was easier to move the tests once
rather than twice.
Standard library and test updates coming separately.
Swift SVN r17056
double-quoted string literals that contain a single extended grapheme cluster
SEGCL by default infer type String, but you can ask to infer Character
for them.
Single quoted literals continue to infer Character.
Actual extended grapheme cluster segmentation is not implemented yet,
<rdar://problem/16755123> Implement extended grapheme cluster
segmentation in libSwiftBasic
This is part of
<rdar://problem/16363872> Remove single quoted characters
Swift SVN r17034
Introduce some infrastructure that allows us to speculatively apply
localized fixes to expressions during constraint solving to fix minor
typos and omissions. At present, we're able to introduce the fixes
during constraint simplification, prefer systems with fewer fixes when
there are multiple fixes, and diagnose the fixes with Fix-Its.
Actually rewriting the AST to reflect what the Fix-Its are doing is
still not handled.
As a start, introduce a fix that adds '()' if it appears to have been
forgotton, producing a diagnostic like this if it works out:
t.swift:8:3: error: function produces expected type 'B'; did you mean
to call it with '()'?
f(g)
^
()
Note that we did regress in one test case
(test/NameBinding/multi-file.swift), because that diagnostic was
getting lucky with the previous formulation.
Swift SVN r16937
Formatting names into strings repeatedly, and using those for semantic
analysis, is generally considered poor form. Additionally, use the
camelCase utilities to perform the string manipulation we need, and
cache results on the ObjCAttr so we don't repeatedly do string
manipulation.
Swift SVN r16334
Language features like erasing concrete metatype
values are also left for the future. Still, baby steps.
The singleton ordinary metatype for existential types
is still potentially useful; we allow it to be written
as P.Protocol.
I've been somewhat cavalier in making code accept
AnyMetatypeType instead of a more specific type, and
it's likely that a number of these places can and
should be more restrictive.
When T is an existential type, parse T.Type as an
ExistentialMetatypeType instead of a MetatypeType.
An existential metatype is the formal type
\exists t:P . (t.Type)
whereas the ordinary metatype is the formal type
(\exists t:P . t).Type
which is singleton. Our inability to express that
difference was leading to an ever-increasing cascade
of hacks where information is shadily passed behind
the scenes in order to make various operations with
static members of protocols work correctly.
This patch takes the first step towards fixing that
by splitting out existential metatypes and giving
them a pointer representation. Eventually, we will
need them to be able to carry protocol witness tables
Swift SVN r15716
We can just get it from the instance type, if the instance type has been fully initialized, which is the case except during parsing of type decls when the decls' own types are being formed.
Swift SVN r15598
(These changes also address the type-check aspects of rdar://problem/16369105, but there are still some SIL generation issues that I need to work through before I can call that work done.)
Swift SVN r15337
In a couple of cases, we weren't properly extracting the correct archetype type from generic type parameters. This was causing various crashes and strange errors throughout the system. (See rdar://problem/16296421, rdar://problem/16273217, rdar://problem/16329242)
Swift SVN r15213
Let ArchetypeType nested types and PotentialArchetypes be bound to concrete types in addition to archetypes. Constraints to outer context archetypes still suffer type-checker issues, but constraints to true concrete types should work now.
Swift SVN r14832
