semantics into the AST library where they don't belong. These were
made obsolete by the recent TypeCheckExpr::build(Member)?RefExpr()
refactoring.
Swift SVN r2222
results of member lookup, and eliminate all uses of
MemberLookup::createResultAST(). The AST library should not be
performing this semantic analysis.
Swift SVN r2221
reference expressions, introducing two routines on TypeChecker
(buildRefExpr and buildMemberRefExpr) that are intended to be the sole
generators of ASTs.
Updated all but one caller for member reference expressions, the
terrible MemberLookup::createResultAST(), which still calls into the
AST library to build nodes.
Swift SVN r2219
base of the expression is ignored, as it will be for references to
static member functions or when the base is actually of metatype
type. Then, always also one to access the type of the base, even if
it's a metatype type.
Use this information to simplify our handling of archetype member
reference expressions, which can refer to either members of the
meta-archetype or of an instance of the archetype. This allows us to
refer to an instance methodr of an archetype type (e.g., T.method) and
get back its curried form ([byref] T) -> inputs -> result.
Swift SVN r2218
used in the very narrow case where we were converting from one
protocol type to another (super) protocol type. However, ErasureExpr
now handles this case via its null conformance entries (for the
"trivial" cases), and can cope with general existential types where
some conversions are trivial and others are not.
The IR generation side of this is basically just a hack to inline the
existing super-conversion code into the erasure code. This whole
routine will eventually need to be reworked anyway to deal with
destination types that are protocol-conformance types and with source
types that are archetypes (for generic/existential interactions).
Swift SVN r2213
conformance when it is trivial, e.g., when the source type is an
archetype or existential type that conforms to the candidate protocol
or a protocol that implies it. In this case, we don't build a
ProtocolConformance structure (which would be uninteresting anyway).
Extend the definition of ErasureExpr to allow for null entries in the
conformance mappings, when some of the conformance is trivial. IRgen
couldn't handle multi-protocol existential types anyway, so this
change has no impact there (yet).
Swift SVN r2212
There are currently two places where you can use a static function defined on a protocol:
on an object with the type of the protocol (discarding the base), and on an archetype in a generic function. The AST for the protocol object case is probably okay;
the AST for the generic case is almost certainly wrong, but that whole area isn't really stable at the moment anyway. The proposal in rdar://problem/11448251 will
add a third way: operators on protocols will be found by overload resolution. (Having static functions on protocols opens up the possibility of metaprotocols,
but I don't think I need to worry about that for the moment.)
Swift SVN r2211
functions. This involves a few steps:
- When assigning archetypes to type parameters, also walk all of the
protocols to which the type parameter conforms and assign archetypes
to each of the associated types.
- When performing name lookup into an archetype, look into all of
the protocols to which it conforms. If we find something, it can be
referenced via the new ArchetypeMemberRefExpr.
- When type-checking ArchetypeMemberRefExpr, substitute the values
of the various associated types into the type of the member, so the
resulting expression involves the archetypes for the enclosing
generic method.
The rest of the type checking essentially follows from the fact that
archetypes are unique types which (therefore) have no behavior beyond
what is provided via the protocols they conform to. However, there is
still much work to do to ensure that we get the archetypes set up
correctly.
Swift SVN r2201
introduce the generic type parameters (which are simply type aliases
for a to-be-determined archetype type) into scope for name
lookup. We can now parse something like
func f<T, U : Range>(x : T, y : U) { }
but there is no semantic analysis or even basic safety checking (yet).
Swift SVN r2197
the member (after reifying the 'this' argument) still refers to any
associated types. We may want to introduce this feature in some
limited capacity later, but it's not important now. The feature is
tracked by <rdar://problem/11689181>.
Swift SVN r2193
and use this information as cues in the language. Right now,
we do not accept things like "-- *i" because the prefix
operator is not correctly right-bound; instead you have to
write "--(*i)". I'm okay with that; I did add a specialized
diagnostic recognizing operator-binary in a place where we're
expecting a potential operator-prefix.
Swift SVN r2161
protocols it conforms to. Use this list when substituting into a
protocol's signature, so that we get an existential type back. For
example:
var e : Enumerable
var r = e.getElements()
r.getFirstAndAdvance() // okay: r is a range.
Swift SVN r2139
protocols the underlying type of the type alias shall conform to. This
isn't super-motivating by itself (one could extend the underying type
instead), but serves as documentation, makes typealiases provide the
same syntax as other nominal types in this regard, and will also be
used to specify requirements on associated types.
Swift SVN r2133
type is either a protocol type or a protocol composition type. The
long form of this query returns the minimal set of protocol
declarations required by that existential type.
Use the new isExistentialType() everywhere that we previously checked
just for ProtocolType, implementing the appropriate rules. Among other
things, this includes:
- Type coercion
- Subtyping relationship
- Checking of explicit protocol conformance
- Member name lookup
Note the FIXME for IR generation; we need to decide how we want to
encode the witnesses for the different protocols.
This is most of <rdar://problem/11548207>.
Swift SVN r2086
protocol conformance types, e.g., 'protocol<P, Q>'. A few things
people *might* want to scream about, or at least scrutinize:
- The parsing of the '<' and '>' is odd, because '<' and '>' aren't
tokens, but are part of the operator grammar. Neither are '>>',
'>>>', '<>', etc., which also come up and need to be parsed
here. Rather than turning anything starting with '<' or '>' into a
different kind of token, I instead parse the initial '<' or '>'
from an operator token and leave the rest of the token as the
remaining operator.
- The canonical form of a protocol-composition type is minimized by
removing any protocols in the list that were inherited by other
protocols in the list, then sorting it. If a singleton list is
left, then the canonical type is simply that protocol type.
- It's a little unfortunate that we now have two existential types
in the system (ProtocolType and ProtocolCompositionType), because
many places will have to check both. Once ProtocolCompositionTypes
are working, we should consider whether it makes sense to remove
ProtocolType.
Still to come: name lookup, coercions.
Swift SVN r2066
