averello/swift-mirror
1
0
Fork 0
mirror of https://github.com/apple/swift.git synced 2025-12-21 12:14:44 +01:00
Code Issues Packages Projects Releases Wiki Activity

[stdlib][swift-3-indexing-model] removing successor/predecessor from String.UnicodeScalarView.Index

Browse Source
This commit is contained in:
Max Moiseev
2016-04-22 16:04:16 -07:00
parent 2a07df42b8
commit e733a9b194
2 changed files with 21 additions and 38 deletions
Download Patch File Download Diff File Expand all files Collapse all files

55
stdlib/public/core/StringUnicodeScalarView.swift
View File

@@ -63,35 +63,6 @@ extension String {
self._core = _core
}
/// Returns the next consecutive value after `self`.
///
/// - Precondition: The next value is representable.
@warn_unused_result
@inline(__always)
internal func successor() -> Index {
// FIXME: swift-3-indexing-model: remove `successor()`.
var scratch = _ScratchIterator(_core, _position)
var decoder = UTF16()
let (_, length) = decoder._decodeOne(&scratch)
return Index(_position + length, _core)
}
/// Returns the previous consecutive value before `self`.
///
/// - Precondition: The previous value is representable.
@warn_unused_result
internal func predecessor() -> Index {
// FIXME: swift-3-indexing-model: remove `predecessor()`.
var i = _position-1
let codeUnit = _core[i]
if _slowPath((codeUnit >> 10) == 0b1101_11) {
if i != 0 && (_core[i - 1] >> 10) == 0b1101_10 {
i -= 1
}
}
return Index(i, _core)
}
/// The end index that for this view.
internal var _viewStartIndex: Index {
return Index(_core.startIndex, _core)
@@ -121,18 +92,30 @@ extension String {
return Index(_core.endIndex, _core)
}
// TODO: swift-3-indexing-model - add docs
/// Returns the next consecutive location after `i`.
///
/// - Precondition: The next location exists.
@warn_unused_result
public func location(after i: Index) -> Index {
// FIXME: swift-3-indexing-model: move `successor()` implementation here.
return i.successor()
var scratch = _ScratchIterator(_core, i._position)
var decoder = UTF16()
let (_, length) = decoder._decodeOne(&scratch)
return Index(i._position + length, _core)
}
// TODO: swift-3-indexing-model - add docs
/// Returns the previous consecutive location before `i`.
///
/// - Precondition: The previous location exists.
@warn_unused_result
public func location(before i: Index) -> Index {
// FIXME: swift-3-indexing-model: move `predecessor()` implementation here.
return i.predecessor()
var i = i._position-1
let codeUnit = _core[i]
if _slowPath((codeUnit >> 10) == 0b1101_11) {
if i != 0 && (_core[i - 1] >> 10) == 0b1101_10 {
i -= 1
}
}
return Index(i, _core)
}
/// Access the element at `position`.
@@ -411,7 +394,7 @@ extension String.UnicodeScalarIndex {
if self == scalars.startIndex || self == scalars.endIndex {
return true
}
let precedingScalar = scalars[self.predecessor()]
let precedingScalar = scalars[scalars.location(before: self)]
let graphemeClusterBreakProperty =
_UnicodeGraphemeClusterBreakPropertyTrie()