Scala Library Documentation
scala.collection

class RollbackIterator
[source: scala/collection/RollbackIterator.scala]
class RollbackIterator[+A](underlying : Iterator[A])
extends DefaultBufferedIterator[A]
Rollback iterators are buffered iterators which allow for unbounded rollbacks
Author
Sean McDirmid
Method Summary
protected def fill : Seq[A]
used to fill lookahead buffer
override def next : A
Returns the next element.
def read (f : => Unit) : Boolean
returns true if any elements are iterated over during f's execution
def readIfStartsWith (seq : Seq[Any]) : Boolean
if elements of seq will be iterated over next in this iterator, returns true and iterates over these elements
def remember [T](g : => (Seq[A]) => T) : T
remembers elements iterated over during g's execution and provides these elements to the result of g's execution
def tryRead [T](f : => Option[T]) : Option[T]
will rollback all elements iterated during f's execution if f return false
Methods inherited from DefaultBufferedIterator
putBack, defaultPeek, hasNext, peekList
Methods inherited from BufferedIterator
head, peek, readIf, readWhile, startsWith, buffered, toString
Methods inherited from Iterator
take, drop, map, append, ++, flatMap, filter, takeWhile, dropWhile, zip, zipWithIndex, foreach, forall, exists, contains, find, foldLeft, foldRight, /:, :\, reduceLeft, reduceRight, counted, duplicate, copyToArray, readInto, readInto, readInto, copyToBuffer, toList, mkString, mkString, addString
Methods inherited from AnyRef
getClass, hashCode, equals, clone, notify, notifyAll, wait, wait, wait, finalize, ==, !=, eq, ne, synchronized
Methods inherited from Any
==, !=, isInstanceOf, asInstanceOf
Method Details
protected def fill : Seq[A]
used to fill lookahead buffer
Overrides
DefaultBufferedIterator.fill
override def next : A
Returns the next element.
Overrides
DefaultBufferedIterator.next
def tryRead[T](f : => Option[T]) : Option[T]
will rollback all elements iterated during f's execution if f return false
def remember[T](g : => (Seq[A]) => T) : T
remembers elements iterated over during g's execution and provides these elements to the result of g's execution
def read(f : => Unit) : Boolean
returns true if any elements are iterated over during f's execution
def readIfStartsWith(seq : Seq[Any]) : Boolean
if elements of seq will be iterated over next in this iterator, returns true and iterates over these elements
Scala Library Documentation