Compare the generic signatures so that we get appropriate partial
ordering among constrained extensions, extensions of inherited
protocols, etc. Finishes rdar://problem/20335936.
Swift SVN r26726
Implement simplistic partial ordering rules for members of protocol
extensions. Specifically:
- A member of a concrete type is more specialized than a member of a
protocol extension
- A member of a protocol extension of P1 is more specialized than a
member of a protocol extension of P2 if P1 inherits from P2
This achieves most of what rdar://problem/20335936 covers, but does
not yet handle ordering between constrained protocol extensions.
Swift SVN r26723
Start parsing a "trailing" where clause for extension declarations, which follows the extended type name and (optional) inheritance clause. Such a where clause is only currently permitted for protocol extensions right now.
When used on a protocol extension, it allows one to create a more-constrained protocol extension, e.g.,
extension CollectionType where Self.Generator.Element : Equatable { ... }
which appears to be working, at least in the obvious cases I've tried.
More cleanup, tests, and penance for the previous commit's "--crash" introductions still to come.
Swift SVN r26689
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 (without associated types, IRGen crashes, etc.)
with methods that can call protocol requirements, generic free
functions, and other methods within the same protocol extension.
This is identical to r26579; the prior commit addressed the underlying
conformance substitution problem that caused rdar://problem/20320393
and subsequent reversion of r26579.
Swift SVN r26639
We do a silly little dance here of finding all of the members of
protocols and their extensions, then deleting the protocol members. In
the future, this is the place where we should handle the protocol
requirement -> witness mapping, including handling derived
conformances.
Basic protocol extensions seem to be working now:
extension SequenceType {
var myCount: Int {
var result = 0
for x in self {
++result
}
return result
}
}
println(["a", "b", "c", "d"].myCount) // 4, duh
Swift SVN r26617
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
