djspiewak / scala-collections

A number of collection implementations for Scala (including a few ported from Clojure)

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Removed cobertura from default build
Daniel Spiewak (author)
Fri Feb 27 09:55:00 -0800 2009
commit  883d4606378fa879ed83120bdde7fa01d608f094
tree    5779872b1a6c549ad3fdd3b302b785d68ff9b33c
parent  f60315249528fd84fc3f1e365636def2210a684b
scala-collections / src / main / scala / com / codecommit / collection / Vector.scala
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ca63f092 » djspiewak 2008-11-13 Added new copyright notice ... 1 /**
2 Copyright (c) 2007-2008, Rich Hickey
3 All rights reserved.
4
5 Redistribution and use in source and binary forms, with or without
6 modification, are permitted provided that the following conditions
7 are met:
8
9 * Redistributions of source code must retain the above copyright
10 notice, this list of conditions and the following disclaimer.
11
12 * Redistributions in binary form must reproduce the above
13 copyright notice, this list of conditions and the following
14 disclaimer in the documentation and/or other materials provided
15 with the distribution.
16
17 * Neither the name of Clojure nor the names of its contributors
18 may be used to endorse or promote products derived from this
19 software without specific prior written permission.
20
21 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
29 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
31 ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32 POSSIBILITY OF SUCH DAMAGE.
33 **/
a802e4bd » djspiewak 2008-10-26 Initial commit 34
35 package com.codecommit.collection
36
37 import Vector._
38
39 /**
40 * A straight port of Clojure's <code>PersistentVector</code> class.
41 *
42 * @author Daniel Spiewak
43 * @author Rich Hickey
44 */
45 class Vector[+T] private (val length: Int, shift: Int, root: Array[AnyRef], tail: Array[AnyRef]) extends RandomAccessSeq[T] { outer =>
46 private val tailOff = length - tail.length
47
48 /*
49 * The design of this data structure inherantly requires heterogenous arrays.
50 * It is *possible* to design around this, but the result is comparatively
51 * quite inefficient. With respect to this fact, I have left the original
52 * (somewhat dynamically-typed) implementation in place.
53 */
54
55 private[collection] def this() = this(0, 5, EmptyArray, EmptyArray)
56
57 def apply(i: Int): T = {
58 if (i >= 0 && i < length) {
59 if (i >= tailOff) {
cd9a39bf » djspiewak 2008-11-13 Replaced tabs with spaces 60 tail(i & 0x01f).asInstanceOf[T]
a802e4bd » djspiewak 2008-10-26 Initial commit 61 } else {
62 var arr = root
63 var level = shift
64
65 while (level > 0) {
66 arr = arr((i >>> level) & 0x01f).asInstanceOf[Array[AnyRef]]
67 level -= 5
68 }
69
70 arr(i & 0x01f).asInstanceOf[T]
71 }
cd9a39bf » djspiewak 2008-11-13 Replaced tabs with spaces 72 } else throw new IndexOutOfBoundsException(i.toString)
a802e4bd » djspiewak 2008-10-26 Initial commit 73 }
74
75 def update[A >: T](i: Int, obj: A): Vector[A] = {
76 if (i >= 0 && i < length) {
77 if (i >= tailOff) {
78 val newTail = new Array[AnyRef](tail.length)
79 Array.copy(tail, 0, newTail, 0, tail.length)
80 newTail(i & 0x01f) = obj.asInstanceOf[AnyRef]
81
82 new Vector[A](length, shift, root, newTail)
cd9a39bf » djspiewak 2008-11-13 Replaced tabs with spaces 83 } else {
a802e4bd » djspiewak 2008-10-26 Initial commit 84 new Vector[A](length, shift, doAssoc(shift, root, i, obj), tail)
85 }
cd9a39bf » djspiewak 2008-11-13 Replaced tabs with spaces 86 } else if (i == length) {
87 this + obj
a802e4bd » djspiewak 2008-10-26 Initial commit 88 } else throw new IndexOutOfBoundsException(i.toString)
89 }
90
91 private def doAssoc[A >: T](level: Int, arr: Array[AnyRef], i: Int, obj: A): Array[AnyRef] = {
92 val ret = new Array[AnyRef](arr.length)
93 Array.copy(arr, 0, ret, 0, arr.length)
94
95 if (level == 0) {
96 ret(i & 0x01f) = obj.asInstanceOf[AnyRef]
cd9a39bf » djspiewak 2008-11-13 Replaced tabs with spaces 97 } else {
a802e4bd » djspiewak 2008-10-26 Initial commit 98 val subidx = (i >>> level) & 0x01f
99 ret(subidx) = doAssoc(level - 5, arr(subidx).asInstanceOf[Array[AnyRef]], i, obj)
cd9a39bf » djspiewak 2008-11-13 Replaced tabs with spaces 100 }
a802e4bd » djspiewak 2008-10-26 Initial commit 101
102 ret
103 }
104
105 override def ++[A >: T](other: Iterable[A]) = other.foldLeft(this:Vector[A]) { _ + _ }
106
107 def +[A >: T](obj: A): Vector[A] = {
108 if (tail.length < 32) {
109 val newTail = new Array[AnyRef](tail.length + 1)
110 Array.copy(tail, 0, newTail, 0, tail.length)
111 newTail(tail.length) = obj.asInstanceOf[AnyRef]
112
113 new Vector[A](length + 1, shift, root, newTail)
cd9a39bf » djspiewak 2008-11-13 Replaced tabs with spaces 114 } else {
a802e4bd » djspiewak 2008-10-26 Initial commit 115 var (newRoot, expansion) = pushTail(shift - 5, root, tail, null)
116 var newShift = shift
117
118 if (expansion != null) {
119 newRoot = array(newRoot, expansion)
120 newShift += 5
121 }
122
123 new Vector[A](length + 1, newShift, newRoot, array(obj.asInstanceOf[AnyRef]))
124 }
125 }
126
127 private def pushTail(level: Int, arr: Array[AnyRef], tailNode: Array[AnyRef], expansion: AnyRef): (Array[AnyRef], AnyRef) = {
128 val newChild = if (level == 0) tailNode else {
129 val (newChild, subExpansion) = pushTail(level - 5, arr(arr.length - 1).asInstanceOf[Array[AnyRef]], tailNode, expansion)
130
131 if (subExpansion == null) {
132 val ret = new Array[AnyRef](arr.length)
133 Array.copy(arr, 0, ret, 0, arr.length)
134
135 ret(arr.length - 1) = newChild
136
137 return (ret, null)
cd9a39bf » djspiewak 2008-11-13 Replaced tabs with spaces 138 } else subExpansion
139 }
a802e4bd » djspiewak 2008-10-26 Initial commit 140
141 // expansion
142 if (arr.length == 32) {
143 (arr, array(newChild))
144 } else {
145 val ret = new Array[AnyRef](arr.length + 1)
146 Array.copy(arr, 0, ret, 0, arr.length)
147 ret(arr.length) = newChild
148
149 (ret, null)
150 }
151 }
152
153 /**
154 * Removes the <i>tail</i> element of this vector.
155 */
156 def pop: Vector[T] = {
157 if (length == 0) {
158 throw new IllegalStateException("Can't pop empty vector")
159 } else if (length == 1) {
160 EmptyVector
161 } else if (tail.length > 1) {
162 val newTail = new Array[AnyRef](tail.length - 1)
163 Array.copy(tail, 0, newTail, 0, newTail.length)
164
165 new Vector[T](length - 1, shift, root, newTail)
cd9a39bf » djspiewak 2008-11-13 Replaced tabs with spaces 166 } else {
a802e4bd » djspiewak 2008-10-26 Initial commit 167 var (newRoot, pTail) = popTail(shift - 5, root, null)
168 var newShift = shift
169
170 if (newRoot == null) {
171 newRoot = EmptyArray
172 }
173
174 if (shift > 5 && newRoot.length == 1) {
175 newRoot = newRoot(0).asInstanceOf[Array[AnyRef]]
176 newShift -= 5
177 }
178
179 new Vector[T](length - 1, newShift, newRoot, pTail.asInstanceOf[Array[AnyRef]])
180 }
181 }
182
183 private def popTail(shift: Int, arr: Array[AnyRef], pTail: AnyRef): (Array[AnyRef], AnyRef) = {
184 val newPTail = if (shift > 0) {
185 val (newChild, subPTail) = popTail(shift - 5, arr(arr.length - 1).asInstanceOf[Array[AnyRef]], pTail)
186
187 if (newChild != null) {
188 val ret = new Array[AnyRef](arr.length)
189 Array.copy(arr, 0, ret, 0, arr.length)
190
191 ret(arr.length - 1) = newChild
192
193 return (ret, subPTail)
cd9a39bf » djspiewak 2008-11-13 Replaced tabs with spaces 194 }
a802e4bd » djspiewak 2008-10-26 Initial commit 195 subPTail
cd9a39bf » djspiewak 2008-11-13 Replaced tabs with spaces 196 } else if (shift == 0) {
a802e4bd » djspiewak 2008-10-26 Initial commit 197 arr(arr.length - 1)
198 } else pTail
199
200 // contraction
201 if (arr.length == 1) {
202 (null, newPTail)
203 } else {
204 val ret = new Array[AnyRef](arr.length - 1)
205 Array.copy(arr, 0, ret, 0, ret.length)
206
207 (ret, newPTail)
208 }
209 }
210
211 override def filter(p: (T)=>Boolean) = {
212 var back = new Vector[T]
213 var i = 0
214
215 while (i < length) {
216 val e = apply(i)
217 if (p(e)) back += e
218
219 i += 1
220 }
221
222 back
223 }
224
225 override def flatMap[A](f: (T)=>Iterable[A]) = {
226 var back = new Vector[A]
227 var i = 0
228
229 while (i < length) {
230 f(apply(i)) foreach { back += _ }
231 i += 1
232 }
233
234 back
235 }
236
237 override def map[A](f: (T)=>A) = {
238 var back = new Vector[A]
239 var i = 0
240
241 while (i < length) {
242 back += f(apply(i))
243 i += 1
244 }
245
246 back
247 }
248
249 override def reverse: Vector[T] = new VectorProjection[T] {
250 override val length = outer.length
251
252 override def apply(i: Int) = outer.apply(length - i - 1)
253 }
254
255 override def subseq(from: Int, end: Int) = subVector(from, end)
256
257 def subVector(from: Int, end: Int): Vector[T] = {
258 if (from < 0) {
259 throw new IndexOutOfBoundsException(from.toString)
260 } else if (end >= length) {
261 throw new IndexOutOfBoundsException(end.toString)
262 } else if (end <= from) {
263 throw new IllegalArgumentException("Invalid range: " + from + ".." + end)
264 } else {
265 new VectorProjection[T] {
266 override val length = end - from
267
268 override def apply(i: Int) = outer.apply(i + from)
269 }
270 }
271 }
272
273 def zip[A](that: Vector[A]) = {
274 var back = new Vector[(T, A)]
275 var i = 0
276
277 val limit = Math.min(length, that.length)
278 while (i < limit) {
279 back += (apply(i), that(i))
280 i += 1
281 }
282
283 back
284 }
285
286 def zipWithIndex = {
287 var back = new Vector[(T, Int)]
288 var i = 0
289
290 while (i < length) {
291 back += (apply(i), i)
292 i += 1
293 }
294
295 back
296 }
297
298 override def equals(other: Any) = other match {
299 case vec:Vector[T] => {
300 var back = length == vec.length
301 var i = 0
302
303 while (i < length) {
304 back &&= apply(i) == vec.apply(i)
305 i += 1
306 }
307
308 back
309 }
310
311 case _ => false
312 }
313
314 override def hashCode = foldLeft(0) { _ ^ _.hashCode }
315 }
316
317 object Vector {
318 private[collection] val EmptyArray = new Array[AnyRef](0)
319
320 def apply[T](elems: T*) = elems.foldLeft(EmptyVector:Vector[T]) { _ + _ }
321
322 def unapplySeq[T](vec: Vector[T]): Option[Seq[T]] = Some(vec)
323
324 @inline
325 private[collection] def array(elems: AnyRef*) = {
326 val back = new Array[AnyRef](elems.length)
327 Array.copy(elems, 0, back, 0, back.length)
328
329 back
330 }
331 }
332
333 object EmptyVector extends Vector[Nothing]
334
335 private[collection] abstract class VectorProjection[+T] extends Vector[T] {
336 override val length: Int
337 override def apply(i: Int): T
338
339 override def +[A >: T](e: A) = innerCopy + e
340
341 override def update[A >: T](i: Int, e: A) = {
342 if (i < 0) {
343 throw new IndexOutOfBoundsException(i.toString)
344 } else if (i > length) {
345 throw new IndexOutOfBoundsException(i.toString)
346 } else innerCopy(i) = e
347 }
348
349 private lazy val innerCopy = foldLeft(EmptyVector:Vector[T]) { _ + _ }
350 }
351