org.abora.white.collection.settable
Class BucketArrayStepper

java.lang.Object
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  +--org.abora.white.xpp.basic.Heaper
        |
        +--org.abora.white.collection.steppers.Stepper
              |
              +--org.abora.white.collection.steppers.TableStepper
                    |
                    +--org.abora.white.collection.settable.BucketArrayStepper

public class BucketArrayStepper

extends TableStepper

Field Summary

protected SharedPtrArray	myEntries
protected TableEntry	myEntry
protected int	myNextBucket
protected static InstanceCache	SomeSteppers

Fields inherited from class org.abora.white.collection.steppers.Stepper

TheEmptyStepper

Constructor Summary

BucketArrayStepper(SharedPtrArray entries, TableEntry entry, int nextBucket)

Method Summary

Stepper	copy() Return a new stepper which steps independently of me, but whose current value is the same as mine, and which must produce a future history of values which satisfies the same obligation that my contract obligates me to produce now.
void	destroy()
void	destruct()
Heaper	fetch() If I am exhausted (i.e., if (!! this->hasValue())), then return NULL.
boolean	hasValue() Iff I have a current value (i.e.
IntegerValue	index() Unboxed version of TableStepper::key.
static TableStepper	make(SharedPtrArray entries)
Position	position() A TableStepper actually enumerates the associations of a table.
void	step() Essential.
void	verifyEntry() Step through the bucket till we find something with a matching key.

Methods inherited from class org.abora.white.collection.steppers.TableStepper

ascending, descending, info, key, stepManyPairs, stepManyPairs

Methods inherited from class org.abora.white.collection.steppers.Stepper

actualHashForEqual, atEnd, emptyStepper, get, isEqual, itemStepper, stepMany, stepMany, theOne

Methods inherited from class org.abora.white.xpp.basic.Heaper

equals, hashForEqual, printContentsOn, printOn, sendSelfTo, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

myEntry

protected TableEntry myEntry

myEntries

protected SharedPtrArray myEntries

myNextBucket

protected int myNextBucket

SomeSteppers

protected static InstanceCache SomeSteppers

Constructor Detail

BucketArrayStepper

public BucketArrayStepper(SharedPtrArray entries,
                          TableEntry entry,
                          int nextBucket)

Method Detail

fetch

public Heaper fetch()

Description copied from class: Stepper

If I am exhausted (i.e., if (!! this->hasValue())), then return NULL. Else return current element. I return wimpily since most items returned are held by collections. If I create a new object, I should cache it.

Specified by:

fetch in class TableStepper

hasValue

public boolean hasValue()

Description copied from class: Stepper

Iff I have a current value (i.e. this message returns true), then I am not exhasted. 'fetch' and 'get' will both return this value, and I can be 'step'ped to my next state. As I am stepped, eventually I may become exhausted (the reverse of all the above), which is a permanent condition. Note that not all steppers have to be exhaustable. A Stepper which enumerates all primes is perfectly reasonable. Assuming otherwise will create infinite loops. See class comment.

Specified by:

hasValue in class TableStepper

step

public void step()

Description copied from class: Stepper

Essential. If I am currently exhausted (see Stepper::hasValue()), then it is an error to step me. The result of doing so isn't currently specified (we probably should specify it to BLAST, but I know that the implementation doesn't currently live up to that spec). If I am not exhausted, then this advances me to my next state. If my current value (see Stepper::get()) was my final value, then I am now exhausted, otherwise my new current value is the next value.

Specified by:

step in class TableStepper

verifyEntry

public void verifyEntry()

Step through the bucket till we find something with a matching key.

index

public IntegerValue index()

Description copied from class: TableStepper

Unboxed version of TableStepper::key. See class comment in XuInteger.

Overrides:

index in class TableStepper

position

public Position position()

Description copied from class: TableStepper

A TableStepper actually enumerates the associations of a table. Through the normal Stepper protocol, it makes available the range element of the current association. Through this additional protocol, it make accessible the key of the current association. This message returns the same object as TwoStepper::other, the only difference being the static knowledge that it's a Position.

Specified by:

position in class TableStepper

destruct

public void destruct()

Overrides:

destruct in class Heaper

copy

public Stepper copy()

Description copied from class: Stepper

Return a new stepper which steps independently of me, but whose current value is the same as mine, and which must produce a future history of values which satisfies the same obligation that my contract obligates me to produce now. Typically, this will mean that he must produce the same future history that I'm going to produce. However, let's say that I am enumerating the elements of a partial order in some full order which is consistent with the partial order. If a copy of me is made after I'm part way through, then me and my copy may produce any future history compatable both with the partial order and the elements I've already produced by the time of the copy. Of course, a subclass or a Stepper creating message (like IntegerRegion::stepper()) may specify the more stringent requirement (that a copy must produce the same sequence). To prevent aliasing, Steppers should typically be passed by copy. See class comment.

Specified by:

copy in class TableStepper

destroy

public void destroy()

Overrides:

destroy in class Heaper

make

public static TableStepper make(SharedPtrArray entries)