refactor slicing to be more type safe.

.gitignore

@@ -4,6 +4,7 @@
 
 # Swift Package Manager
 .build/
+.swiftpm
 
 DerivedData/
 

Sources/NdArray/Equitable.swift

@@ -50,7 +50,7 @@ extension NdArray: Equatable where T: Equatable {
  // make sure the array is not sliced
  let a = NdArray(lhs)
  let b = NdArray(rhs)
- for i in 0..<a.shape[0] where a[i] != b[i] {
+ for i in 0..<a.shape[0] where a[[Slice(i)]] != b[[Slice(i)]] {
  return false
  }
  }

Sources/NdArray/Matrix.swift

@@ -102,7 +102,7 @@ open class Matrix<T>: NdArray<T> {
  Cannot transpose matrix with shape \(shape) to matrix with shape \(out.shape).
  Precondition failed while trying to transpose \(debugDescription) to \(out.debugDescription).
  """)
- out[...][...] = self.transposed()[...][...]
+ out[0..., 0...] = self.transposed()[0..., 0...]
  }
  }
 }
@@ -167,11 +167,11 @@ public extension Matrix where T == Double {
  return B
  }
  // copy rhs to work space (thereby also making sure it is F contiguous)
- B[...] = rhs[...]
+ B[0...] = rhs[0...]
 
  // copy self to A, since it is modified (thereby also making sure it is F contiguous)
  let A = Matrix<T>(empty: shape, order: .F)
- A[...] = self[...]
+ A[0...] = self[0...]
  var nrhs = __CLPK_integer(B.shape[1])
  var ipiv: [__CLPK_integer] = [__CLPK_integer].init(repeating: 0, count: Int(n))
  var lda: __CLPK_integer = __CLPK_integer(n)
@@ -202,7 +202,7 @@ public extension Matrix where T == Double {
  Precondition failed while trying to solve \(debugDescription).
  """)
  let A = out ?? Matrix(empty: shape, order: .F)
- A[...] = self[...]
+ A[0...] = self[0...]
 
  var ipiv = try A.luFactor()
 
@@ -326,11 +326,11 @@ public extension Matrix where T == Float {
  return B
  }
  // copy rhs to work space (thereby also making sure it is F contiguous)
- B[...] = rhs[...]
+ B[0...] = rhs[0...]
 
  // copy self to A, since it is modified (thereby also making sure it is F contiguous)
  let A = Matrix<T>(empty: shape, order: .F)
- A[...] = self[...]
+ A[0...] = self[0...]
  var nrhs = __CLPK_integer(B.shape[1])
  var ipiv: [__CLPK_integer] = [__CLPK_integer].init(repeating: 0, count: Int(n))
  var lda: __CLPK_integer = __CLPK_integer(n)
@@ -361,7 +361,7 @@ public extension Matrix where T == Float {
  Precondition failed while trying to solve \(debugDescription).
  """)
  let A = out ?? Matrix(empty: shape, order: .F)
- A[...] = self[...]
+ A[0...] = self[0...]
 
  var ipiv = try A.luFactor()
 

Sources/NdArray/NdArray.swift

@@ -99,7 +99,7 @@ open class NdArray<T>: CustomDebugStringConvertible,
  self.count = a.count
  self.shape = a.shape
  self.strides = a.strides
- precondition(self !== owner)
+ assert(self !== owner)
  }
 
  deinit {
@@ -247,17 +247,20 @@ open class NdArray<T>: CustomDebugStringConvertible,
  "\(self, style: .multiLine)"
  }
 
- /// element access
+ /**
+ element access
+ */
  public subscript(index: [Int]) -> T {
  get {
  data[flatIndex(index)]
  }
  set {
- self.data[flatIndex(index)] = newValue
+ data[flatIndex(index)] = newValue
  }
  }
 
  /// full slice access
+ @available(*, deprecated, message: "prefer new slicing syntax a[0..., 0..., 0...] over old one a[...][...][...]")
  public subscript(r: UnboundedRange) -> NdArray<T> {
  get {
  NdArraySlice(self, sliced: 0)[r]
@@ -268,6 +271,7 @@ open class NdArray<T>: CustomDebugStringConvertible,
  }
 
  /// partial range slice access
+ @available(*, deprecated, message: "prefer new slicing syntax a[0...42, 0...42, 0...42] over old one a[0...42][0...42][0...42]")
  public subscript(r: ClosedRange<Int>) -> NdArray<T> {
  get {
  NdArraySlice(self, sliced: 0)[r]
@@ -278,6 +282,7 @@ open class NdArray<T>: CustomDebugStringConvertible,
  }
 
  /// partial range slice access
+ @available(*, deprecated, message: "prefer new slicing syntax a[...42, ...42, ...42] over old one a[...42][...42][...42]")
  public subscript(r: PartialRangeThrough<Int>) -> NdArray<T> {
  get {
  NdArraySlice(self, sliced: 0)[r]
@@ -288,6 +293,7 @@ open class NdArray<T>: CustomDebugStringConvertible,
  }
 
  /// partial range slice access
+ @available(*, deprecated, message: "prefer new slicing syntax a[..<42, ..<42, ..<42] over old one a[..<42][..<42][..<42]")
  public subscript(r: PartialRangeUpTo<Int>) -> NdArray<T> {
  get {
  NdArraySlice(self, sliced: 0)[r]
@@ -298,6 +304,7 @@ open class NdArray<T>: CustomDebugStringConvertible,
  }
 
  /// partial range slice access
+ @available(*, deprecated, message: "prefer new slicing syntax a[42..., 42.., 42..] over old one a[42...][42...][42...]")
  public subscript(r: PartialRangeFrom<Int>) -> NdArray<T> {
  get {
  NdArraySlice(self, sliced: 0)[r]
@@ -308,6 +315,7 @@ open class NdArray<T>: CustomDebugStringConvertible,
  }
 
  /// range slice access
+ @available(*, deprecated, message: "prefer new slicing syntax a[1..<42, 1..<42, 1..<42] over old one a[1..<42][1..<42][1..<42]")
  public subscript(r: Range<Int>) -> NdArray<T> {
  get {
  NdArraySlice(self, sliced: 0)[r]
@@ -318,6 +326,7 @@ open class NdArray<T>: CustomDebugStringConvertible,
  }
 
  /// range with stride
+ @available(*, deprecated, message: "prefer new slicing syntax a[1..<42 ~ 3, 1..<42 ~ 3, 1..<42 ~ 3] over old one a[1..<42, 3][1..<42, 3][1..<42, 3]")
  public subscript(r: Range<Int>, stride: Int) -> NdArray<T> {
  get {
  NdArraySlice(self, sliced: 0)[r, stride]
@@ -328,6 +337,7 @@ open class NdArray<T>: CustomDebugStringConvertible,
  }
 
  /// closed range with stride
+ @available(*, deprecated, message: "prefer new slicing syntax a[0...42 ~ 3, 0...42 ~ 3, 0...42 ~ 3] over old one a[0...42, 3][0...42, 3][0...42, 3]")
  public subscript(r: ClosedRange<Int>, stride: Int) -> NdArray<T> {
  get {
  NdArraySlice(self, sliced: 0)[r, stride]
@@ -338,6 +348,7 @@ open class NdArray<T>: CustomDebugStringConvertible,
  }
 
  /// partial range with stride
+ @available(*, deprecated, message: "prefer new slicing syntax a[42... ~ 3, 42.. ~ 3, 42.. ~ 3] over old one a[42..., 3][42..., 3][42..., 3]")
  public subscript(r: PartialRangeFrom<Int>, stride: Int) -> NdArray<T> {
  get {
  NdArraySlice(self, sliced: 0)[r, stride]
@@ -348,6 +359,7 @@ open class NdArray<T>: CustomDebugStringConvertible,
  }
 
  /// partial range with stride
+ @available(*, deprecated, message: "prefer new slicing syntax a[...42 ~ 3, ...42 ~ 3, ...42 ~ 3] over old one a[...42, 3][...42, 3][...42, 3]")
  public subscript(r: PartialRangeThrough<Int>, stride: Int) -> NdArray<T> {
  get {
  NdArraySlice(self, sliced: 0)[r, stride]
@@ -358,6 +370,7 @@ open class NdArray<T>: CustomDebugStringConvertible,
  }
 
  /// partial range with stride
+ @available(*, deprecated, message: "prefer new slicing syntax a[..<42 ~ 3, ..<42 ~ 3, ..<42 ~ 3] over old one a[..<42, 3][..<42, 3][..<42, 3]")
  public subscript(r: PartialRangeUpTo<Int>, stride: Int) -> NdArray<T> {
  get {
  NdArraySlice(self, sliced: 0)[r, stride]
@@ -368,6 +381,7 @@ open class NdArray<T>: CustomDebugStringConvertible,
  }
 
  /// full range with stride
+ @available(*, deprecated, message: "prefer new slicing syntax a[0... ~ 3, 0... ~ 3, 0... ~ 3] over old one a[..., 3][..., 3][..., 3]")
  public subscript(r: UnboundedRange, stride: Int) -> NdArray<T> {
  get {
  NdArraySlice(self, sliced: 0)[r, stride]
@@ -378,6 +392,7 @@ open class NdArray<T>: CustomDebugStringConvertible,
  }
 
  /// single slice access
+ @available(*, deprecated, message: "prefer new slicing syntax a[42, 42, 42] over old one a[42][42][42]")
  public subscript(i: Int) -> NdArray<T> {
  get {
  precondition(!isEmpty)
@@ -402,6 +417,47 @@ open class NdArray<T>: CustomDebugStringConvertible,
  newValue.copyTo(self[i])
  }
  }
+
+ /**
+ slice access
+ */
+ public subscript(slices: [Slice]) -> NdArray<T> {
+ get {
+ var a = NdArraySlice(self, sliced: 0)
+ for (i, s) in slices.enumerated() {
+ switch s.sliceKind {
+ case .range(lowerBound: let lowerBound, upperBound: let upperBound, stride: let stride):
+ let stride = stride ?? 1
+ let lowerBound = lowerBound ?? 0
+ let upperBound = upperBound ?? shape[i]
+ a = a.subscr(lowerBound: lowerBound, upperBound: upperBound, stride: stride)
+ case .index(let i):
+ a = a.subscr(i)
+ if a.shape.isEmpty {
+ a.shape = [1]
+ a.strides = [1]
+ a.count = 1
+ }
+ }
+ }
+ return NdArray(a)
+ }
+ set {
+ newValue.copyTo(self[slices])
+ }
+ }
+
+ /**
+ slice access
+ */
+ public subscript(slices: Slice...) -> NdArray<T> {
+ get {
+ self[slices]
+ }
+ set {
+ self[slices] = newValue
+ }
+ }
 }
 
 // extension helping to handle different memory alignments

Sources/NdArray/NdArraySlice.swift

@@ -4,7 +4,7 @@
 
 import Darwin
 
-public class NdArraySlice<T>: NdArray<T> {
+internal class NdArraySlice<T>: NdArray<T> {
  /// number of dimensions that have been sliced
  private var sliced: Int
 
@@ -50,7 +50,7 @@ public class NdArraySlice<T>: NdArray<T> {
  private func subscr(_ r: UnboundedRange) -> NdArraySlice {
  let slice = NdArraySlice(self, sliced: sliced + 1)
  slice.sliceDescription = sliceDescription
- slice.sliceDescription.append("[...]")
+ slice.sliceDescription.append("[0...]")
  return slice
  }
 
@@ -141,6 +141,8 @@ public class NdArraySlice<T>: NdArray<T> {
  let slice = NdArraySlice(self, startIndex: [Int](repeating: 0, count: ndim), sliced: sliced + 1)
  slice.shape[sliced] = 0
  slice.count = slice.len
+ slice.sliceDescription = sliceDescription
+ slice.sliceDescription.append("[\(r.lowerBound)..<\(r.upperBound)]")
  return slice
  }
 
@@ -200,7 +202,7 @@ public class NdArraySlice<T>: NdArray<T> {
  /// partial range with stride
  public override subscript(r: PartialRangeFrom<Int>, stride: Int) -> NdArray<T> {
  get {
- precondition(stride > 0, "\(stride) > 0")
+ precondition(stride > 0, "\(stride) > 0, \(debugDescription)")
 
  let slice = self.subscr(r)
  slice.sliceDescription.removeLast()
@@ -287,6 +289,34 @@ public class NdArraySlice<T>: NdArray<T> {
  }
  }
 
+ internal func subscr(lowerBound: Int, upperBound: Int, stride: Int) -> NdArraySlice<T> {
+ precondition(stride > 0, "\(stride) > 0")
+
+ let slice = self.subscr(lowerBound..<upperBound)
+ slice.sliceDescription.removeLast()
+ slice.sliceDescription.append("[\(lowerBound)..<\(upperBound), \(stride)]")
+ slice.strideBy(stride, axis: sliced)
+ return slice
+ }
+
+ internal func subscr(_ i: Int) -> NdArraySlice<T> {
+ precondition(!isEmpty)
+
+ // set the index on the sliced dimension
+ var startIndex = [Int](repeating: 0, count: ndim)
+ startIndex[sliced] = i
+
+ // here we reduce the shape, hence sliced stays the same
+ let slice = NdArraySlice(self, startIndex: startIndex, sliced: sliced)
+ slice.sliceDescription = sliceDescription
+ slice.sliceDescription.append("[\(i)]")
+ // drop shape and stride
+ slice.shape = Array(slice.shape[0..<sliced] + slice.shape[(sliced + 1)...])
+ slice.strides = Array(slice.strides[0..<sliced] + slice.strides[(sliced + 1)...])
+ slice.count = slice.len
+ return slice
+ }
+
  public override var debugDescription: String {
  let address = String(format: "%p", Int(bitPattern: data))
  var sliceDescription = sliceDescription.joined()