Class UnicodeSetIterator

java.lang.Object
com.ibm.icu.text.UnicodeSetIterator
public final class UnicodeSetIterator extends Object
UnicodeSetIterator iterates over the contents of a UnicodeSet. It iterates over either code points or code point ranges. After all code points or ranges have been returned, it returns the multicharacter strings of the UnicodeSet, if any.

This class is not intended for public subclassing.

To iterate over code points and multicharacter strings, use a loop like this: 

for (UnicodeSetIterator it = new UnicodeSetIterator(set); it.next();) {
  processString(it.getString());
}

To iterate over code point ranges, use a loop like this: 

for (UnicodeSetIterator it = new UnicodeSetIterator(set); it.nextRange();) {
  if (it.codepoint != UnicodeSetIterator.IS_STRING) {
    processCodepointRange(it.codepoint, it.codepointEnd);
  } else {
    processString(it.getString());
  }
}

To iterate over only the strings, start with new UnicodeSetIterator(set).skipToStrings() .

Warning: For speed, UnicodeSet iteration does not check for concurrent modification. Do not alter the UnicodeSet while iterating.

Author:
M. Davis
See Also:
Status:
Stable ICU 2.0.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    int
    codepoint
    Current code point, or the special value IS_STRING, if the iterator points to a string.
    int
    codepointEnd
    When iterating over ranges using nextRange(), codepointEnd contains the inclusive end of the iteration range, if codepoint != IS_STRING.
    static final int
    IS_STRING
    Value of codepoint if the iterator points to a string.
    String
    string
    If codepoint == IS_STRING, then string points to the current string.

  • Constructor Summary

    Constructors
    Constructor
    Description
    UnicodeSetIterator()
    Create an iterator over nothing.
    UnicodeSetIterator(UnicodeSet set)
    Create an iterator over the given set.

  • Method Summary

    Modifier and Type
    Method
    Description
    String
    getString()
    Gets the current string from the iterator.
    boolean
    next()
    Returns the next element in the set, either a single code point or a string.
    boolean
    nextRange()
    Returns the next element in the set, either a code point range or a string.
    void
    reset()
    Resets this iterator to the start of the set.
    void
    reset(UnicodeSet uset)
    Sets this iterator to visit the elements of the given set and resets it to the start of that set.
    UnicodeSetIterator
    skipToStrings()
    Skips over the remaining code points/ranges, if any.

    Methods inherited from class Object

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

  • Field Details

    • IS_STRING

      public static final int IS_STRING
      Value of codepoint if the iterator points to a string. If codepoint == IS_STRING, then examine string for the current iteration result.
      See Also:
      Status:
      Stable ICU 2.0.

    • codepoint

      public int codepoint
      Current code point, or the special value IS_STRING, if the iterator points to a string.
      Status:
      Stable ICU 2.0.

    • codepointEnd

      public int codepointEnd
      When iterating over ranges using nextRange(), codepointEnd contains the inclusive end of the iteration range, if codepoint != IS_STRING. If iterating over code points using next(), or if codepoint == IS_STRING, then the value of codepointEnd is undefined.
      Status:
      Stable ICU 2.0.

    • string

      public String string
      If codepoint == IS_STRING, then string points to the current string. If codepoint != IS_STRING, the value of string is undefined.
      Status:
      Stable ICU 2.0.

  • Constructor Details

    • UnicodeSetIterator

      public UnicodeSetIterator(UnicodeSet set)
      Create an iterator over the given set.
      Parameters:
      set - set to iterate over
      Status:
      Stable ICU 2.0.

    • UnicodeSetIterator

      public UnicodeSetIterator()
      Create an iterator over nothing. next() and nextRange() return false. This is a convenience constructor allowing the target to be set later.
      Status:
      Stable ICU 2.0.

  • Method Details

    • skipToStrings

      public UnicodeSetIterator skipToStrings()
      Skips over the remaining code points/ranges, if any. A following call to next() or nextRange() will yield a string, if there is one. No-op if next() would return false, or if it would yield a string anyway.
      Returns:
      this
      See Also:
      Status:
      Stable ICU 70.

    • next

      public boolean next()
      Returns the next element in the set, either a single code point or a string. If there are no more elements in the set, return false. If codepoint == IS_STRING, the value is a string in the string field. Otherwise the value is a single code point in the codepoint field.

      The order of iteration is all code points in sorted order, followed by all strings sorted order. codepointEnd is undefined after calling this method. string is undefined unless codepoint == IS_STRING. Do not mix calls to next() and nextRange() without calling reset() between them. The results of doing so are undefined.

      Warning: For speed, UnicodeSet iteration does not check for concurrent modification. Do not alter the UnicodeSet while iterating.

      Returns:
      true if there was another element in the set and this object contains the element.
      Status:
      Stable ICU 2.0.

    • nextRange

      public boolean nextRange()
      Returns the next element in the set, either a code point range or a string. If there are no more elements in the set, return false. If codepoint == IS_STRING, the value is a string in the string field. Otherwise the value is a range of one or more code points from codepoint to codepointeEnd inclusive.

      The order of iteration is all code points ranges in sorted order, followed by all strings sorted order. Ranges are disjoint and non-contiguous. string is undefined unless codepoint == IS_STRING. Do not mix calls to next() and nextRange() without calling reset() between them. The results of doing so are undefined.

      Returns:
      true if there was another element in the set and this object contains the element.
      Status:
      Stable ICU 2.0.

    • reset

      public void reset(UnicodeSet uset)
      Sets this iterator to visit the elements of the given set and resets it to the start of that set. The iterator is valid only so long as set is valid.
      Parameters:
      uset - the set to iterate over.
      Status:
      Stable ICU 2.0.

    • reset

      public void reset()
      Resets this iterator to the start of the set.
      Status:
      Stable ICU 2.0.

    • getString

      public String getString()
      Gets the current string from the iterator. Only use after calling next(), not nextRange().
      Status:
      Stable ICU 4.0.