mirror of
https://github.com/apple/swift.git
synced 2025-12-21 12:14:44 +01:00
e24f2ba6e5
The optimizer dislikes nested switch statements; flatten them out to simplify optimization and to hopefully speed things up a little.
109 lines
4.0 KiB
Swift
109 lines
4.0 KiB
Swift
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This source file is part of the Swift.org open source project
|
|
//
|
|
// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
|
|
// Licensed under Apache License v2.0 with Runtime Library Exception
|
|
//
|
|
// See https://swift.org/LICENSE.txt for license information
|
|
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
//===--- Compiler conversion/casting entry points for Dictionary<K, V> ----===//
|
|
|
|
/// Perform a non-bridged upcast that always succeeds.
|
|
///
|
|
/// - Precondition: `BaseKey` and `BaseValue` are base classes or base `@objc`
|
|
/// protocols (such as `AnyObject`) of `DerivedKey` and `DerivedValue`,
|
|
/// respectively.
|
|
@inlinable
|
|
public func _dictionaryUpCast<DerivedKey, DerivedValue, BaseKey, BaseValue>(
|
|
_ source: Dictionary<DerivedKey, DerivedValue>
|
|
) -> Dictionary<BaseKey, BaseValue> {
|
|
var result = Dictionary<BaseKey, BaseValue>(minimumCapacity: source.count)
|
|
|
|
for (k, v) in source {
|
|
result[k as! BaseKey] = (v as! BaseValue)
|
|
}
|
|
return result
|
|
}
|
|
|
|
/// Called by the casting machinery.
|
|
@_silgen_name("_swift_dictionaryDownCastIndirect")
|
|
internal func _dictionaryDownCastIndirect<SourceKey, SourceValue,
|
|
TargetKey, TargetValue>(
|
|
_ source: UnsafePointer<Dictionary<SourceKey, SourceValue>>,
|
|
_ target: UnsafeMutablePointer<Dictionary<TargetKey, TargetValue>>) {
|
|
target.initialize(to: _dictionaryDownCast(source.pointee))
|
|
}
|
|
|
|
/// Implements a forced downcast. This operation should have O(1) complexity.
|
|
///
|
|
/// The cast can fail if bridging fails. The actual checks and bridging can be
|
|
/// deferred.
|
|
///
|
|
/// - Precondition: `DerivedKey` is a subtype of `BaseKey`, `DerivedValue` is
|
|
/// a subtype of `BaseValue`, and all of these types are reference types.
|
|
@inlinable
|
|
public func _dictionaryDownCast<BaseKey, BaseValue, DerivedKey, DerivedValue>(
|
|
_ source: Dictionary<BaseKey, BaseValue>
|
|
) -> Dictionary<DerivedKey, DerivedValue> {
|
|
|
|
#if _runtime(_ObjC)
|
|
if _isClassOrObjCExistential(BaseKey.self)
|
|
&& _isClassOrObjCExistential(BaseValue.self)
|
|
&& _isClassOrObjCExistential(DerivedKey.self)
|
|
&& _isClassOrObjCExistential(DerivedValue.self) {
|
|
|
|
guard source._variant.isNative else {
|
|
return Dictionary(
|
|
_immutableCocoaDictionary: source._variant.asCocoa.object)
|
|
}
|
|
// Note: it is safe to treat the buffer as immutable here because
|
|
// Dictionary will not mutate buffer with reference count greater than 1.
|
|
return Dictionary(
|
|
_immutableCocoaDictionary: source._variant.asNative.bridged())
|
|
}
|
|
#endif
|
|
return _dictionaryDownCastConditional(source)!
|
|
}
|
|
|
|
/// Called by the casting machinery.
|
|
@_silgen_name("_swift_dictionaryDownCastConditionalIndirect")
|
|
internal func _dictionaryDownCastConditionalIndirect<SourceKey, SourceValue,
|
|
TargetKey, TargetValue>(
|
|
_ source: UnsafePointer<Dictionary<SourceKey, SourceValue>>,
|
|
_ target: UnsafeMutablePointer<Dictionary<TargetKey, TargetValue>>
|
|
) -> Bool {
|
|
if let result: Dictionary<TargetKey, TargetValue>
|
|
= _dictionaryDownCastConditional(source.pointee) {
|
|
target.initialize(to: result)
|
|
return true
|
|
}
|
|
return false
|
|
}
|
|
|
|
/// Implements a conditional downcast.
|
|
///
|
|
/// If the cast fails, the function returns `nil`. All checks should be
|
|
/// performed eagerly.
|
|
///
|
|
/// - Precondition: `DerivedKey` is a subtype of `BaseKey`, `DerivedValue` is
|
|
/// a subtype of `BaseValue`, and all of these types are reference types.
|
|
@inlinable
|
|
public func _dictionaryDownCastConditional<
|
|
BaseKey, BaseValue, DerivedKey, DerivedValue
|
|
>(
|
|
_ source: Dictionary<BaseKey, BaseValue>
|
|
) -> Dictionary<DerivedKey, DerivedValue>? {
|
|
|
|
var result = Dictionary<DerivedKey, DerivedValue>()
|
|
for (k, v) in source {
|
|
guard let k1 = k as? DerivedKey, let v1 = v as? DerivedValue
|
|
else { return nil }
|
|
result[k1] = v1
|
|
}
|
|
return result
|
|
}
|