bool ArraySpec::operator<=(const ArraySpec& rhs) const {
auto const& lhs = *this;
if (lhs == Bottom || rhs == Top) return true;
if (lhs == Top || rhs == Bottom) return false;
// It's possible to subtype RAT::Array types, but it's potentially O(n), so
// we just don't do it.
return (!rhs.kind() || lhs.kind() == rhs.kind()) &&
(!rhs.type() || lhs.type() == rhs.type()) &&
(!rhs.shape() || lhs.shape() == rhs.shape());
}
// Return true if the array satisfies requirement on the ArraySpec.
static bool arrayFitsSpec(const ArrayData* arr, const ArraySpec spec) {
if (spec == ArraySpec::Top) return true;
if (auto const spec_kind = spec.kind()) {
if (arr->kind() == spec_kind) return true;
}
if (auto const rat_type = spec.type()) {
using A = RepoAuthType::Array;
if (arr->empty() && rat_type->emptiness() != A::Empty::No) return true;
if (arr->isVectorData()) {
switch (rat_type->tag()) {
case A::Tag::Packed:
if (arr->size() != rat_type->size()) break;
// fall through
case A::Tag::PackedN: {
int64_t k = 0;
for ( ; k < arr->size(); ++k) {
auto const specElemType =
rat_type->tag() == A::Tag::Packed ? rat_type->packedElem(k)
: rat_type->elemType();
if (!tvMatchesRepoAuthType(*(arr->get(k).asTypedValue()),
specElemType)) {
break;
}
}
if (k == arr->size()) return true;
break;
}
}
}
}
return false;
}
ArraySpec ArraySpec::operator|(const ArraySpec& rhs) const {
auto const& lhs = *this;
if (lhs <= rhs) return rhs;
if (rhs <= lhs) return lhs;
// Take the union componentwise. Components union trivially (i.e., to
// "unspecialized") unless they are equal.
auto new_kind = lhs.kind() == rhs.kind() ? lhs.kind() : folly::none;
auto new_type = lhs.type() == rhs.type() ? lhs.type() : nullptr;
// If the shapes were nontrivial and equal, the specs would be equal.
assertx(!lhs.shape() || lhs.shape() != rhs.shape());
// Nontrivial kind /and/ type unions would imply equal kinds and types.
assertx(!new_kind || !new_type);
if (new_kind) return ArraySpec(*new_kind);
if (new_type) return ArraySpec(new_type);
return Top;
}