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PeekingIterator (Guava Libraries 2010.01.04)
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com.google.common.collect</FONT>
<BR>
Interface PeekingIterator<E></H2>
<DL>
<DT><B>All Superinterfaces:</B> <DD><A HREF="http://java.sun.com/javase/6/docs/api/java/util/Iterator.html?is-external=true" title="class or interface in java.util">Iterator</A><E></DD>
</DL>
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<DL>
<DT><PRE>public interface <B>PeekingIterator<E></B><DT>extends <A HREF="http://java.sun.com/javase/6/docs/api/java/util/Iterator.html?is-external=true" title="class or interface in java.util">Iterator</A><E></DL>
</PRE>
<P>
An iterator that supports a one-element lookahead while iterating.
<P>
<P>
<DL>
<DT><B>Since:</B></DT>
<DD>2010.01.04 <b>stable</b> (imported from Google Collections Library)</DD>
<DT><B>Author:</B></DT>
<DD>Mick Killianey</DD>
</DL>
<HR>
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<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../com/google/common/collect/PeekingIterator.html" title="type parameter in PeekingIterator">E</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../com/google/common/collect/PeekingIterator.html#next()">next</A></B>()</CODE>
<BR>
</TD>
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<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> <A HREF="../../../../com/google/common/collect/PeekingIterator.html" title="type parameter in PeekingIterator">E</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../com/google/common/collect/PeekingIterator.html#peek()">peek</A></B>()</CODE>
<BR>
Returns the next element in the iteration, without advancing the iteration.</TD>
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<TD ALIGN="right" VALIGN="top" WIDTH="1%"><FONT SIZE="-1">
<CODE> void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../com/google/common/collect/PeekingIterator.html#remove()">remove</A></B>()</CODE>
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<TH ALIGN="left"><B>Methods inherited from interface java.util.<A HREF="http://java.sun.com/javase/6/docs/api/java/util/Iterator.html?is-external=true" title="class or interface in java.util">Iterator</A></B></TH>
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<TD><CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/util/Iterator.html?is-external=true#hasNext()" title="class or interface in java.util">hasNext</A></CODE></TD>
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<A NAME="peek()"><!-- --></A><H3>
peek</H3>
<PRE>
<A HREF="../../../../com/google/common/collect/PeekingIterator.html" title="type parameter in PeekingIterator">E</A> <B>peek</B>()</PRE>
<DL>
<DD>Returns the next element in the iteration, without advancing the iteration.
<p>Calls to <code>peek()</code> should not change the state of the iteration,
except that it <i>may</i> prevent removal of the most recent element via
<A HREF="../../../../com/google/common/collect/PeekingIterator.html#remove()"><CODE>remove()</CODE></A>.
<P>
<DD><DL>
</DL>
</DD>
<DD><DL>
<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/util/NoSuchElementException.html?is-external=true" title="class or interface in java.util">NoSuchElementException</A></CODE> - if the iteration has no more elements
according to <A HREF="http://java.sun.com/javase/6/docs/api/java/util/Iterator.html?is-external=true#hasNext()" title="class or interface in java.util"><CODE>Iterator.hasNext()</CODE></A></DL>
</DD>
</DL>
<HR>
<A NAME="next()"><!-- --></A><H3>
next</H3>
<PRE>
<A HREF="../../../../com/google/common/collect/PeekingIterator.html" title="type parameter in PeekingIterator">E</A> <B>next</B>()</PRE>
<DL>
<DD>
<p>The objects returned by consecutive calls to <A HREF="../../../../com/google/common/collect/PeekingIterator.html#peek()"><CODE>peek()</CODE></A> then <A HREF="../../../../com/google/common/collect/PeekingIterator.html#next()"><CODE>next()</CODE></A> are guaranteed to be equal to each other.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/util/Iterator.html?is-external=true#next()" title="class or interface in java.util">next</A></CODE> in interface <CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/util/Iterator.html?is-external=true" title="class or interface in java.util">Iterator</A><<A HREF="../../../../com/google/common/collect/PeekingIterator.html" title="type parameter in PeekingIterator">E</A>></CODE></DL>
</DD>
<DD><DL>
</DL>
</DD>
</DL>
<HR>
<A NAME="remove()"><!-- --></A><H3>
remove</H3>
<PRE>
void <B>remove</B>()</PRE>
<DL>
<DD>
<p>Implementations may or may not support removal when a call to <A HREF="../../../../com/google/common/collect/PeekingIterator.html#peek()"><CODE>peek()</CODE></A> has occurred since the most recent call to <A HREF="../../../../com/google/common/collect/PeekingIterator.html#next()"><CODE>next()</CODE></A>.
<P>
<DD><DL>
<DT><B>Specified by:</B><DD><CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/util/Iterator.html?is-external=true#remove()" title="class or interface in java.util">remove</A></CODE> in interface <CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/util/Iterator.html?is-external=true" title="class or interface in java.util">Iterator</A><<A HREF="../../../../com/google/common/collect/PeekingIterator.html" title="type parameter in PeekingIterator">E</A>></CODE></DL>
</DD>
<DD><DL>
<DT><B>Throws:</B>
<DD><CODE><A HREF="http://java.sun.com/javase/6/docs/api/java/lang/IllegalStateException.html?is-external=true" title="class or interface in java.lang">IllegalStateException</A></CODE> - if there has been a call to <A HREF="../../../../com/google/common/collect/PeekingIterator.html#peek()"><CODE>peek()</CODE></A>
since the most recent call to <A HREF="../../../../com/google/common/collect/PeekingIterator.html#next()"><CODE>next()</CODE></A> and this implementation
does not support this sequence of calls (optional)</DL>
</DD>
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