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/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2002-2009, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
// $Id$
package scala
import scala.collection.mutable.{Map, HashMap}
import scala.collection.immutable.{Set, BitSet}
import scala.collection.generic.{Builder, BuilderFactory, AddingBuilder, SetTemplate}
/** <p>
* Defines a finite set of values specific to the enumeration. Typically
* these values enumerate all possible forms something can take and provide a
* lightweight alternative to case classes.
* </p>
* <p>
* Each call to a <code>Value</code> method adds a new unique value to the
* enumeration. To be accessible, these values are usually defined as
* <code>val</code> members of the evaluation.
* </p>
* <p>
* All values in an enumeration share a common, unique type defined as the
* <code>Value</code> type member of the enumeration (<code>Value</code>
* selected on the stable identifier path of the enumeration instance).
* </p>
* <p>
* <b>Example use</b>
* </p><pre>
* <b>object</b> Main <b>extends</b> Application {
*
* <b>object</b> WeekDay <b>extends</b> Enumeration {
* <b>type</b> WeekDay</b> = Value
* <b>val</b> Mon, Tue, Wed, Thu, Fri, Sat, Sun = Value
* }
* <b>import</b> WeekDay._
*
* <b>def</b> isWorkingDay(d: WeekDay) = ! (d == Sat || d == Sun)
*
* WeekDay.elements filter isWorkingDay foreach println
* }</pre>
*
* @param initial The initial value from which to count the integers that
* identifies values at run-time.
* @param names The sequence of names to give to this enumeration's values.
*
* @author Matthias Zenger
* @version 1.0, 10/02/2004
*/
@serializable
@SerialVersionUID(8476000850333817230L)
abstract class Enumeration(initial: Int, names: String*) {
def this() = this(0, null)
def this(names: String*) = this(0, names: _*)
/** The name of this enumeration.
*/
override def toString = {
val cname = this.getClass().getName()
if (cname endsWith "$")
cname.substring(0, cname.length() - 1)
else if (cname endsWith "$class")
cname.substring(0, cname.length() - 6)
else
cname
}
/** The mapping from the integer used to identifying values to the actual
* values. */
private val vmap: Map[Int, Value] = new HashMap
/** The cache listing all values of this enumeration. */
@transient private var vset: ValueSet = null
@transient private var vsetDefined = false
/** The values of this enumeration as a set.
*/
def values: ValueSet = {
if (!vsetDefined) {
vset = new ValueSet(BitSet.empty ++ (vmap.values map (_.id)))
vsetDefined = true
}
vset
}
/** The integer to use to identify the next created value. */
protected var nextId = initial
/** The string to use to name the next created value. */
protected var nextName = names.elements
/** The highest integer amongst those used to identify values in this
* enumeration. */
private var topId = initial
/** The highest integer amongst those used to identify values in this
* enumeration. */
final def maxId = topId
/** The value of this enumeration with given id `x`
*/
final def apply(x: Int): Value = vmap(x)
/** Returns a Value from this Enumeration whose name matches
* the argument <var>s</var>.
* You must pass a String* set of names to the constructor,
* or initialize each Enumeration with Value(String),
* for valueOf to work.
* @param s an enumeration name
* @return <tt>Some(Value)</tt> if an enumeration's name matches <var>s</var>,
* else <tt>None</tt>
*/
def withName(s: String): Value = values.find(_.toString == s).get
/** Creates a fresh value, part of this enumeration. */
protected final def Value: Value = Value(nextId)
/** Creates a fresh value, part of this enumeration, identified by the integer
* <code>i</code>.
*
* @param i An integer that identifies this value at run-time. It must be
* unique amongst all values of the enumeration.
* @return ..
*/
protected final def Value(i: Int): Value =
Value(i, if (nextName.hasNext) nextName.next else null)
/** Creates a fresh value, part of this enumeration, called <code>name</code>.
*
* @param name A human-readable name for that value.
*/
protected final def Value(name: String): Value = Value(nextId, name)
/** Creates a fresh value, part of this enumeration, called <code>name</code>
* and identified by the integer <code>i</code>.
*
* @param i An integer that identifies this value at run-time. It must be
* unique amongst all values of the enumeration.
* @param name A human-readable name for that value.
* @return ..
*/
protected final def Value(i: Int, name: String): Value = new Val(i, name)
/** The type of the enumerated values. */
@serializable
@SerialVersionUID(7091335633555234129L)
abstract class Value extends Ordered[Value] {
/** the id and bit location of this enumeration value */
def id: Int
override def compare(that: Value): Int = this.id - that.id
override def equals(other: Any): Boolean =
other match {
case that: Value => compare(that) == 0
case _ => false
}
override def hashCode: Int = id.hashCode
/** this enumeration value as an <code>Int</code> bit mask.
* @throws IllegalArgumentException if <code>id</code> is greater than 31
* @deprecated
*/
@deprecated def mask32: Int = {
if (id >= 32) throw new IllegalArgumentException
1 << id
}
/** this enumeration value as an <code>Long</code> bit mask.
* @throws IllegalArgumentException if <code>id</code> is greater than 63
* @deprecated
*/
@deprecated def mask64: Long = {
if (id >= 64) throw new IllegalArgumentException
1L << id
}
}
/** A class implementing the <a href="Enumeration.Value.html"
* target="contentFrame"><code>Value</code></a> type. This class can be
* overriden to change the enumeration's naming and integer identification
* behaviour.
*/
@serializable
@SerialVersionUID(0 - 3501153230598116017L)
protected class Val(i: Int, name: String) extends Value {
def this(i: Int) =
this(i, if (nextName.hasNext) nextName.next else i.toString())
def this(name: String) = this(nextId, name)
def this() =
this(nextId, if (nextName.hasNext) nextName.next else nextId.toString())
assert(!vmap.isDefinedAt(i))
vmap(i) = this
vsetDefined = false
nextId = i + 1
if (nextId > topId) topId = nextId
def id = i
override def toString() =
if (name eq null) Enumeration.this + "(" + i + ")"
else name
private def readResolve(): AnyRef =
if (vmap ne null) vmap(i)
else this
}
/** A class for sets of values
* Iterating through this set will yield values in increasing order of their ids.
* @param ids The set of ids of values, organized as a BitSet.
*/
class ValueSet private[Enumeration] (val ids: BitSet) extends Set[Value] with SetTemplate[Value, ValueSet] {
override def empty = ValueSet.empty
def contains(v: Value) = ids contains (v.id)
def plus (value: Value) = new ValueSet(ids + value.id)
def minus (value: Value) = new ValueSet(ids - value.id)
def elements = ids.elements map Enumeration.this.apply
override def stringPrefix = Enumeration.this + ".ValueSet"
}
/** A factory object for value sets */
object ValueSet {
/** The empty value set */
val empty = new ValueSet(BitSet.empty)
/** A value set consisting of given elements */
def apply(elems: Value*): ValueSet = {
var s = empty
for (elem <- elems) s = s + elem // !!! change to s += elem --> error
s
}
/** A builder object for value sets */
def newBuilder: Builder[Value, ValueSet] = new AddingBuilder(empty)
/** The implicit builder for value sets */
implicit def builderFactory: BuilderFactory[Value, ValueSet, ValueSet] = new BuilderFactory[Value, ValueSet, ValueSet] { def apply(from: ValueSet) = newBuilder }
}
}
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