1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
|
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2002-2006, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala
import compat.Platform.arraycopy
/** This object ...
*
* @author Martin Odersky
* @version 1.0
*/
object Array {
/** Copy one array to another.
* Equivalent to
* <code>System.arraycopy(src, srcPos, dest, destPos, length)</code>,
* except that this works also for polymorphic and boxed arrays.
*
* @param src ...
* @param srcPos ...
* @param dest ...
* @param destPos ...
* @param length ...
*/
def copy(src: AnyRef, srcPos: Int, dest: AnyRef, destPos: Int, length: Int): Unit = src match {
case xs: runtime.BoxedArray =>
xs.copyTo(srcPos, dest, destPos, length)
case _ =>
dest match {
case xs: runtime.BoxedArray =>
xs.copyFrom(src, srcPos, destPos, length)
case _ =>
arraycopy(src, srcPos, dest, destPos, length)
}
}
/** Concatenate all argument arrays into a single array.
*
* @param xs ...
*/
def concat[T](xs: Array[T]*) = {
var len = 0
for (val x <- xs) {
len = len + x.length
}
val result = new Array[T](len)
var start = 0
for (val x <- xs) {
copy(x, 0, result, start, x.length)
start = start + x.length
}
result
}
/** Create a an array containing of successive integers.
*
* @param from the value of the first element of the array
* @param end the value of the last element fo the array plus 1
* @return the sorted array of all integers in range [from;end).
*/
def range(start: Int, end: Int): Array[Int] = {
val result = new Array[Int](end - start)
for (val i <- Iterator.range(start, end)) result(i - start) = i
result
}
/** Create an array with given elements.
*
* @param xs the elements to put in the array
* @return the array containing elements xs.
*/
def apply[A <: AnyRef](xs: A*): Array[A] = {
val array = new Array[A](xs.length)
var i = 0
for (val x <- xs.elements) { array(i) = x; i = i + 1; }
array
}
/* The following metod clashes with the previous one, and has therefore been
* removed. Note that this is a choice between efficiency and generality.
* The previous factory method is more efficient than the one that has been
* commented out. Since it is anyway possible to create a polymorphic array
* using
* new Array[T]
* it was preferred to restrict the definition of the factory method.
def Array[A](xs: A*): Array[A] = {
val array = new Array[A](xs.length)
var i = 0
for (val x <- xs.elements) { array(i) = x; i = i + 1; }
array
}
*/
def apply(xs: Boolean*): Array[Boolean] = {
val array = new Array[Boolean](xs.length)
var i = 0
for (val x <- xs.elements) { array(i) = x; i = i + 1; }
array
}
def apply(xs: Byte*): Array[Byte] = {
val array = new Array[Byte](xs.length)
var i = 0
for (val x <- xs.elements) { array(i) = x; i = i + 1; }
array
}
def apply(xs: Short*): Array[Short] = {
val array = new Array[Short](xs.length)
var i = 0
for (val x <- xs.elements) { array(i) = x; i = i + 1; }
array
}
def apply(xs: Char*): Array[Char] = {
val array = new Array[Char](xs.length)
var i = 0
for (val x <- xs.elements) { array(i) = x; i = i + 1; }
array
}
def apply(xs: Int*): Array[Int] = {
val array = new Array[Int](xs.length)
var i = 0
for (val x <- xs.elements) { array(i) = x; i = i + 1; }
array
}
def apply(xs: Long*): Array[Long] = {
val array = new Array[Long](xs.length)
var i = 0
for (val x <- xs.elements) { array(i) = x; i = i + 1; }
array
}
def apply(xs: Float*): Array[Float] = {
val array = new Array[Float](xs.length)
var i = 0
for (val x <- xs.elements) { array(i) = x; i = i + 1; }
array
}
def apply(xs: Double*): Array[Double] = {
val array = new Array[Double](xs.length)
var i = 0
for (val x <- xs.elements) { array(i) = x; i = i + 1; }
array
}
def apply(xs: Unit*): Array[Unit] = {
val array = new Array[Unit](xs.length)
var i = 0
for (val x <- xs.elements) { array(i) = x; i = i + 1; }
array
}
/** Create an array containing several copies of an element.
*
* @param n the length of the resulting array
* @param elem the element composing the resulting array
* @return an array composed of n elements all equal to elem
*/
def make[a](n: Int, elem: a): Array[a] = {
val a = new Array[a](n)
var i = 0
while (i < n) {
a(i) = elem
i = i + 1
}
a
}
/** This method is called in a pattern match { case Array(...) => }.
*
* @param x the selector value
* @return array wrapped in an option, if this is a Seq, otherwise none
*/
def unapplySeq[A](x: Any): Option[Seq[A]] =
if (x.isInstanceOf[Array[A]]) Some(x.asInstanceOf[Array[A]]) else None
}
/** This class represents polymorphic arrays. It is never instantiated.
*
* @author Martin Odersky
* @version 1.0
*/
final class Array[A](_length: Int) extends Seq[A] {
import Predef.Error
/** The length of the array */
def length: Int = throw new Error()
/** The element at given index.
* Indices start a <code>0</code>; <code>xs.apply(0)</code> is the first
* element of array <code>xs</code>.
* Note the indexing syntax <code>xs(i)</code> is a shorthand for <code>xs.apply(i)</code>.
* @param i the index
* @throws ArrayIndexOutOfBoundsException if <code>i < 0</code> or
* <code>length <= i</code>
*/
def apply(i: Int): A = throw new Error()
/** Update the element at given index.
* Indices start a <code>0</code>; <code>xs.apply(0)</code> is the first
* element of array <code>xs</code>.
* Note the indexing syntax <code>xs(i) = x</code> is a shorthand
* for <code>xs.update(i, x)</code>.
* @param i the index
* @param x the value to be written at index <code>i</code>
* @throws ArrayIndexOutOfBoundsException if <code>i < 0</code> or
* <code>length <= i</code>
*/
def update(i: Int, x: A): Unit = throw new Error()
/** An iterator returning the elements of this array, starting from 0.
*/
def elements: Iterator[A] = throw new Error()
/** @deprecated use slice instead */
def subArray(from: Int, end: Int): Array[A] = throw new Error()
/** A sub-array of <code>len</code> elements
* starting at index <code>from</code>
* @param from The index of the first element of the slice
* @param end The index of the element following the slice
* @throws IndexOutOfBoundsException if <code>from < 0</code>
* or <code>length < from + len<code>
*/
override def slice(from: Int, end: Int): Array[A] = throw new Error()
/** Returns an array consisting of all elements of this array that satisfy the
* predicate <code>p</code>. The order of the elements is preserved.
*
* @param p the predicate used to filter the array.
* @return the elements of this array satisfying <code>p</code>.
*/
override def filter(p: A => Boolean): Array[A] = throw new Error()
/** Returns the array resulting from applying the given function <code>f</code> to each
* element of this array.
*
* @param f function to apply to each element.
* @return <code>[f(a0), ..., f(an)]</code> if this array is <code>[a0, ..., an]</code>.
*/
override def map[B](f: A => B): Array[B] = throw new Error()
/** Applies the given function <code>f</code> to each element of
* this array, then concatenates the results.
*
* @param f the function to apply on each element.
* @return <code>f(a<sub>0</sub>) ::: ... ::: f(a<sub>n</sub>)</code> if
* this array is <code>[a<sub>0</sub>, ..., a<sub>n</sub>]</code>.
*/
override def flatMap[B](f: A => Iterable[B]): Array[B] = throw new Error()
/** Returns an array formed from this array and the specified array
* <code>that</code> by associating each element of the former with
* the element at the same position in the latter.
* If one of the two arrays is longer than the other, its remaining elements are ignored.
*
* @return <code>Array({a<sub>0</sub>,b<sub>0</sub>}, ...,
* {a<sub>min(m,n)</sub>,b<sub>min(m,n)</sub>})</code> when
* <code>Array(a<sub>0</sub>, ..., a<sub>m</sub>)
* zip Array(b<sub>0</sub>, ..., b<sub>n</sub>)</code> is invoked.
*/
def zip[B](that: Array[B]): Array[Tuple2[A,B]] = throw new Error()
/** Returns an array that pairs each element of this array
* with its index, counting from 0.
*
* @return the array <code>Array({a<sub>0</sub>,0}, {a<sub>1</sub>,1},...)</code>
* where <code>a<sub>i</sub></code> are the elements of this stream.
*/
def zipWithIndex: Array[Tuple2[A,Int]] = throw new Error()
}
|
