Package com.ibm.icu.text

Class 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:
    UnicodeSet.ranges(), UnicodeSet.strings(), UnicodeSet.iterator()
    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 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.

    • Field Detail

      • 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:
        Constant Field Values
        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 Detail

      • 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 Detail

      • 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:
        UnicodeSet.strings()
        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.