Retire the old components now that the new ones have passed API review.
<rdar://20406937> covers the migration fallout of this change.
Swift SVN r26904
- 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
We were ending up looking in the parent context, but it didn't matter
because the parser pre-resolved the names of generic parameters. We
shouldn't be relying on the parser to do that.
Note that this regresses four compiler crashes, because they end up
looking back into their own generic parameter lists in unhealthy
ways. I'm going to temporarily burn some karma because of what this
enables...
Swift SVN r26688
Remove the semantic restrictions that prohibited extensions of
protocol types, and start making some systematic changes so that
protocol extensions start to make sense:
- Replace a lot of occurrences of isa<ProtocolDecl> and
dyn_cast<ProtocolDecl> on DeclContexts to use the new
DeclContext::isProtocolOrProtocolExtensionContext(), where we want
that behavior to apply equally to protocols and protocol extensions.
- Eliminate ProtocolDecl::getSelf() in favor of
DeclContext::getProtocolSelf(), which produces the appropriate
generic type parameter for the 'Self' of a protocol or protocol
extension. Update all of the callers of ProtocolDecl::getSelf()
appropriately.
- Update extension validation to appropriately form generic
parameter lists for protocol extensions.
- Methods in protocol extensions always use the witnesscc calling
convention.
At this point, we can type check and SILGen very basic definitions of
protocol extensions with methods that can call protocol requirements,
generic free functions, and other methods within the same protocol
extension.
Regresses four compiler crashers but improves three compiler
crashers... we'll call that "progress"; the four regressions all hit
the same assertion in the constraint system that will likely be
addressed as protocol extensions starts working.
Swift SVN r26579
Having semantic checking in type validation introduces the potential for more recursion, triggering crashes. By moving this semantic restriction out to a later stage, we make it more robust. Fixes 6 compiler crashers, although it regressed one compiler crasher that hits a different known issue (assertions in addGenericParameters when we have multiple parameters at the same depth).
Swift SVN r26226
Previously, a multi-pattern var/let decl like:
var x = 4, y = 17
would produce two pattern binding decls (one for x=4 one for y=17). This is convenient
in some ways, but is bad for source reproducibility from the ASTs (see, e.g. the improvements
in test/IDE/structure.swift and test/decl/inherit/initializer.swift).
The hardest part of this change was to get parseDeclVar to set up the AST in a way
compatible with our existing assumptions. I ended up with an approach that forms PBDs in
more erroneous cases than before. One downside of this is that we now produce a spurious
"type annotation missing in pattern"
diagnostic in some cases. I'll take care of that in a follow-on patch.
Swift SVN r26224
requires pushing the types out. The only interesting one is this diff:
- var (e,f,g:(),h) = MRV()
+ var (e,f,g,h) : (Int, Float, (), Double) = MRV()
... where the type annotation is required to silence the warning about "void type
may be unexpected". This seems perfectly reasonable to me.
Swift SVN r26161
This changes 'if let' conditions to take general refutable patterns, instead of
taking a irrefutable pattern and implicitly matching against an optional.
Where before you might have written:
if let x = foo() {
you now need to write:
if let x? = foo() {
The upshot of this is that you can write anything in an 'if let' that you can
write in a 'case let' in a switch statement, which is pretty general.
To aid with migration, this special cases certain really common patterns like
the above (and any other irrefutable cases, like "if let (a,b) = foo()", and
tells you where to insert the ?. It also special cases type annotations like
"if let x : AnyObject = " since they are no longer allowed.
For transitional purposes, I have intentionally downgraded the most common
diagnostic into a warning instead of an error. This means that you'll get:
t.swift:26:10: warning: condition requires a refutable pattern match; did you mean to match an optional?
if let a = f() {
^
?
I think this is important to stage in, because this is a pretty significant
source breaking change and not everyone internally may want to deal with it
at the same time. I filed 20166013 to remember to upgrade this to an error.
In addition to being a nice user feature, this is a nice cleanup of the guts
of the compiler, since it eliminates the "isConditional()" bit from
PatternBindingDecl, along with the special case logic in the compiler to handle
it (which variously added and removed Optional around these things).
Swift SVN r26150
a let/var pattern. Now any identifier in one of these is a variable binding,
not sometimes a value references (depending on contextual syntax).
This isn't expected to have a widespread effect on existing real world code:
- No impact on the stdlib.
- It does fix two validation crash tests, but possibly because the original issue is hidden by a different diagnostic path in the compiler.
- This needed two tests to be tweaked to undistribute "let".
On the positive side, this means that "case let x?:" now works properly, woo.
Swift SVN r26000
These APIs will be used for writing automation tools in Swift. Just
like other private APIs, this module is not exposed to extrenal users.
The primary motivation for doing instead of using NSCoder this is that
NSCoder does not work with structs and Swift containers. Using classes
for everything just to satisfy NSCoder forces unnatural code.
This API requires two times (!) less boilerplate than NSCoding, since
the same method is used for serialization and deserialization. This API
is also more type-safe, it does not require the user to write 'as' type
casts, unlike NSCoding.
Please take a look at
validation-test/stdlib/SwiftPrivateSerialization.swift to see the
intended use pattern.
The performance of the underlying implementation is already decent, and
there's a lot of room for improvement.
This is a re-commit of r25678, with a fix for 32-bit platforms.
Swift SVN r25877
The standard library has grown significantly, and we need a new
directory structure that clearly reflects the role of the APIs, and
allows future growth.
See stdlib/{public,internal,private}/README.txt for more information.
Swift SVN r25876
