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Diffstat (limited to 'examples/scala-js/scalalib/overrides-2.10/scala/collection/immutable/Range.scala')
| -rw-r--r-- | examples/scala-js/scalalib/overrides-2.10/scala/collection/immutable/Range.scala | 424 |
1 files changed, 424 insertions, 0 deletions
diff --git a/examples/scala-js/scalalib/overrides-2.10/scala/collection/immutable/Range.scala b/examples/scala-js/scalalib/overrides-2.10/scala/collection/immutable/Range.scala new file mode 100644 index 0000000..5c8758d --- /dev/null +++ b/examples/scala-js/scalalib/overrides-2.10/scala/collection/immutable/Range.scala @@ -0,0 +1,424 @@ +/* __ *\ +** ________ ___ / / ___ Scala API ** +** / __/ __// _ | / / / _ | (c) 2006-2013, LAMP/EPFL ** +** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ ** +** /____/\___/_/ |_/____/_/ | | ** +** |/ ** +\* */ + + +package scala.collection.immutable + +import scala.collection.parallel.immutable.ParRange + +/** The `Range` class represents integer values in range + * ''[start;end)'' with non-zero step value `step`. + * It's a special case of an indexed sequence. + * For example: + * + * {{{ + * val r1 = 0 until 10 + * val r2 = r1.start until r1.end by r1.step + 1 + * println(r2.length) // = 5 + * }}} + * + * @param start the start of this range. + * @param end the exclusive end of the range. + * @param step the step for the range. + * + * @author Martin Odersky + * @author Paul Phillips + * @version 2.8 + * @since 2.5 + * @see [[http://docs.scala-lang.org/overviews/collections/concrete-immutable-collection-classes.html#ranges "Scala's Collection Library overview"]] + * section on `Ranges` for more information. + * + * @define coll range + * @define mayNotTerminateInf + * @define willNotTerminateInf + * @define doesNotUseBuilders + * '''Note:''' this method does not use builders to construct a new range, + * and its complexity is O(1). + */ +@SerialVersionUID(7618862778670199309L) +@inline +class Range(val start: Int, val end: Int, val step: Int) +extends scala.collection.AbstractSeq[Int] + with IndexedSeq[Int] + with scala.collection.CustomParallelizable[Int, ParRange] + with Serializable +{ + override def par = new ParRange(this) + + private def gap = end.toLong - start.toLong + private def isExact = gap % step == 0 + private def hasStub = isInclusive || !isExact + private def longLength = gap / step + ( if (hasStub) 1 else 0 ) + + // Check cannot be evaluated eagerly because we have a pattern where + // ranges are constructed like: "x to y by z" The "x to y" piece + // should not trigger an exception. So the calculation is delayed, + // which means it will not fail fast for those cases where failing was + // correct. + override final val isEmpty = ( + (start > end && step > 0) + || (start < end && step < 0) + || (start == end && !isInclusive) + ) + final val numRangeElements: Int = { + if (step == 0) throw new IllegalArgumentException("step cannot be 0.") + else if (isEmpty) 0 + else { + val len = longLength + if (len > scala.Int.MaxValue) -1 + else len.toInt + } + } + final val lastElement = start + (numRangeElements - 1) * step + final val terminalElement = start + numRangeElements * step + + override def last = if (isEmpty) Nil.last else lastElement + + override def min[A1 >: Int](implicit ord: Ordering[A1]): Int = + if (ord eq Ordering.Int) { + if (step > 0) start + else last + } else super.min(ord) + + override def max[A1 >: Int](implicit ord: Ordering[A1]): Int = + if (ord eq Ordering.Int) { + if (step > 0) last + else start + } else super.max(ord) + + protected def copy(start: Int, end: Int, step: Int): Range = new Range(start, end, step) + + /** Create a new range with the `start` and `end` values of this range and + * a new `step`. + * + * @return a new range with a different step + */ + def by(step: Int): Range = copy(start, end, step) + + def isInclusive = false + + override def size = length + override def length = if (numRangeElements < 0) fail() else numRangeElements + + private def fail() = Range.fail(start, end, step, isInclusive) + private def validateMaxLength() { + if (numRangeElements < 0) + fail() + } + + def validateRangeBoundaries(f: Int => Any): Boolean = { + validateMaxLength() + + start != Int.MinValue || end != Int.MinValue || { + var count = 0 + var num = start + while (count < numRangeElements) { + f(num) + count += 1 + num += step + } + false + } + } + + final def apply(idx: Int): Int = { + validateMaxLength() + if (idx < 0 || idx >= numRangeElements) throw new IndexOutOfBoundsException(idx.toString) + else start + (step * idx) + } + + @inline final override def foreach[@specialized(Unit) U](f: Int => U) { + validateMaxLength() + val isCommonCase = (start != Int.MinValue || end != Int.MinValue) + var i = start + var count = 0 + val terminal = terminalElement + val step = this.step + while( + if(isCommonCase) { i != terminal } + else { count < numRangeElements } + ) { + f(i) + count += 1 + i += step + } + } + + /** Creates a new range containing the first `n` elements of this range. + * + * $doesNotUseBuilders + * + * @param n the number of elements to take. + * @return a new range consisting of `n` first elements. + */ + final override def take(n: Int): Range = ( + if (n <= 0 || isEmpty) newEmptyRange(start) + else if (n >= numRangeElements) this + else new Range.Inclusive(start, locationAfterN(n - 1), step) + ) + + /** Creates a new range containing all the elements of this range except the first `n` elements. + * + * $doesNotUseBuilders + * + * @param n the number of elements to drop. + * @return a new range consisting of all the elements of this range except `n` first elements. + */ + final override def drop(n: Int): Range = ( + if (n <= 0 || isEmpty) this + else if (n >= numRangeElements) newEmptyRange(end) + else copy(locationAfterN(n), end, step) + ) + + /** Creates a new range containing all the elements of this range except the last one. + * + * $doesNotUseBuilders + * + * @return a new range consisting of all the elements of this range except the last one. + */ + final override def init: Range = { + if (isEmpty) + Nil.init + + dropRight(1) + } + + /** Creates a new range containing all the elements of this range except the first one. + * + * $doesNotUseBuilders + * + * @return a new range consisting of all the elements of this range except the first one. + */ + final override def tail: Range = { + if (isEmpty) + Nil.tail + + drop(1) + } + + // Counts how many elements from the start meet the given test. + private def skipCount(p: Int => Boolean): Int = { + var current = start + var counted = 0 + + while (counted < numRangeElements && p(current)) { + counted += 1 + current += step + } + counted + } + // Tests whether a number is within the endpoints, without testing + // whether it is a member of the sequence (i.e. when step > 1.) + private def isWithinBoundaries(elem: Int) = !isEmpty && ( + (step > 0 && start <= elem && elem <= last ) || + (step < 0 && last <= elem && elem <= start) + ) + // Methods like apply throw exceptions on invalid n, but methods like take/drop + // are forgiving: therefore the checks are with the methods. + private def locationAfterN(n: Int) = start + (step * n) + + // When one drops everything. Can't ever have unchecked operations + // like "end + 1" or "end - 1" because ranges involving Int.{ MinValue, MaxValue } + // will overflow. This creates an exclusive range where start == end + // based on the given value. + private def newEmptyRange(value: Int) = new Range(value, value, step) + + final override def takeWhile(p: Int => Boolean): Range = take(skipCount(p)) + final override def dropWhile(p: Int => Boolean): Range = drop(skipCount(p)) + final override def span(p: Int => Boolean): (Range, Range) = splitAt(skipCount(p)) + + /** Creates a pair of new ranges, first consisting of elements before `n`, and the second + * of elements after `n`. + * + * $doesNotUseBuilders + */ + final override def splitAt(n: Int) = (take(n), drop(n)) + + /** Creates a new range consisting of the `length - n` last elements of the range. + * + * $doesNotUseBuilders + */ + final override def takeRight(n: Int): Range = drop(numRangeElements - n) + + /** Creates a new range consisting of the initial `length - n` elements of the range. + * + * $doesNotUseBuilders + */ + final override def dropRight(n: Int): Range = take(numRangeElements - n) + + /** Returns the reverse of this range. + * + * $doesNotUseBuilders + */ + final override def reverse: Range = + if (isEmpty) this + else new Range.Inclusive(last, start, -step) + + /** Make range inclusive. + */ + def inclusive = + if (isInclusive) this + else new Range.Inclusive(start, end, step) + + final def contains(x: Int) = isWithinBoundaries(x) && ((x - start) % step == 0) + + final override def sum[B >: Int](implicit num: Numeric[B]): Int = { + if (isEmpty) 0 + else if (numRangeElements == 1) head + else (numRangeElements.toLong * (head + last) / 2).toInt + } + + override def toIterable = this + + override def toSeq = this + + override def equals(other: Any) = other match { + case x: Range => + (x canEqual this) && (length == x.length) && ( + isEmpty || // all empty sequences are equal + (start == x.start && last == x.last) // same length and same endpoints implies equality + ) + case _ => + super.equals(other) + } + /** Note: hashCode can't be overridden without breaking Seq's + * equals contract. + */ + + override def toString() = { + val endStr = if (numRangeElements > Range.MAX_PRINT) ", ... )" else ")" + take(Range.MAX_PRINT).mkString("Range(", ", ", endStr) + } +} + +/** A companion object for the `Range` class. + */ +object Range { + private[immutable] val MAX_PRINT = 512 // some arbitrary value + + private def description(start: Int, end: Int, step: Int, isInclusive: Boolean) = + "%d %s %d by %s".format(start, if (isInclusive) "to" else "until", end, step) + + private def fail(start: Int, end: Int, step: Int, isInclusive: Boolean) = + throw new IllegalArgumentException(description(start, end, step, isInclusive) + + ": seqs cannot contain more than Int.MaxValue elements.") + + /** Counts the number of range elements. + * @pre step != 0 + * If the size of the range exceeds Int.MaxValue, the + * result will be negative. + */ + def count(start: Int, end: Int, step: Int, isInclusive: Boolean): Int = { + if (step == 0) + throw new IllegalArgumentException("step cannot be 0.") + + val isEmpty = ( + if (start == end) !isInclusive + else if (start < end) step < 0 + else step > 0 + ) + if (isEmpty) 0 + else { + // Counts with Longs so we can recognize too-large ranges. + val gap: Long = end.toLong - start.toLong + val jumps: Long = gap / step + // Whether the size of this range is one larger than the + // number of full-sized jumps. + val hasStub = isInclusive || (gap % step != 0) + val result: Long = jumps + ( if (hasStub) 1 else 0 ) + + if (result > scala.Int.MaxValue) -1 + else result.toInt + } + } + def count(start: Int, end: Int, step: Int): Int = + count(start, end, step, false) + + @inline + class Inclusive(start: Int, end: Int, step: Int) extends Range(start, end, step) { +// override def par = new ParRange(this) + override def isInclusive = true + override protected def copy(start: Int, end: Int, step: Int): Range = new Inclusive(start, end, step) + } + + /** Make a range from `start` until `end` (exclusive) with given step value. + * @note step != 0 + */ + def apply(start: Int, end: Int, step: Int): Range = new Range(start, end, step) + + /** Make a range from `start` until `end` (exclusive) with step value 1. + */ + def apply(start: Int, end: Int): Range = new Range(start, end, 1) + + /** Make an inclusive range from `start` to `end` with given step value. + * @note step != 0 + */ + def inclusive(start: Int, end: Int, step: Int): Range.Inclusive = new Inclusive(start, end, step) + + /** Make an inclusive range from `start` to `end` with step value 1. + */ + def inclusive(start: Int, end: Int): Range.Inclusive = new Inclusive(start, end, 1) + + // BigInt and Long are straightforward generic ranges. + object BigInt { + def apply(start: BigInt, end: BigInt, step: BigInt) = NumericRange(start, end, step) + def inclusive(start: BigInt, end: BigInt, step: BigInt) = NumericRange.inclusive(start, end, step) + } + + object Long { + def apply(start: Long, end: Long, step: Long) = NumericRange(start, end, step) + def inclusive(start: Long, end: Long, step: Long) = NumericRange.inclusive(start, end, step) + } + + // BigDecimal uses an alternative implementation of Numeric in which + // it pretends to be Integral[T] instead of Fractional[T]. See Numeric for + // details. The intention is for it to throw an exception anytime + // imprecision or surprises might result from anything, although this may + // not yet be fully implemented. + object BigDecimal { + implicit val bigDecAsIntegral = scala.math.Numeric.BigDecimalAsIfIntegral + + def apply(start: BigDecimal, end: BigDecimal, step: BigDecimal) = + NumericRange(start, end, step) + def inclusive(start: BigDecimal, end: BigDecimal, step: BigDecimal) = + NumericRange.inclusive(start, end, step) + } + + // Double works by using a BigDecimal under the hood for precise + // stepping, but mapping the sequence values back to doubles with + // .doubleValue. This constructs the BigDecimals by way of the + // String constructor (valueOf) instead of the Double one, which + // is necessary to keep 0.3d at 0.3 as opposed to + // 0.299999999999999988897769753748434595763683319091796875 or so. + object Double { + implicit val bigDecAsIntegral = scala.math.Numeric.BigDecimalAsIfIntegral + implicit val doubleAsIntegral = scala.math.Numeric.DoubleAsIfIntegral + def toBD(x: Double): BigDecimal = scala.math.BigDecimal valueOf x + + def apply(start: Double, end: Double, step: Double) = + BigDecimal(toBD(start), toBD(end), toBD(step)) mapRange (_.doubleValue) + + def inclusive(start: Double, end: Double, step: Double) = + BigDecimal.inclusive(toBD(start), toBD(end), toBD(step)) mapRange (_.doubleValue) + } + + // As there is no appealing default step size for not-really-integral ranges, + // we offer a partially constructed object. + class Partial[T, U](f: T => U) { + def by(x: T): U = f(x) + } + + // Illustrating genericity with Int Range, which should have the same behavior + // as the original Range class. However we leave the original Range + // indefinitely, for performance and because the compiler seems to bootstrap + // off it and won't do so with our parameterized version without modifications. + object Int { + def apply(start: Int, end: Int, step: Int) = NumericRange(start, end, step) + def inclusive(start: Int, end: Int, step: Int) = NumericRange.inclusive(start, end, step) + } +} |