Class CodePointTrie

java.lang.Object
com.ibm.icu.util.CodePointMap
com.ibm.icu.util.CodePointTrie
All Implemented Interfaces:
Iterable<CodePointMap.Range>
Direct Known Subclasses:
CodePointTrie.Fast, CodePointTrie.Small

public abstract class CodePointTrie extends CodePointMap
Immutable Unicode code point trie. Fast, reasonably compact, map from Unicode code points (U+0000..U+10FFFF) to integer values. For details see https://icu.unicode.org/design/struct/utrie

This class is not intended for public subclassing.

See Also:
  • Field Details

    • data

      @Deprecated protected final com.ibm.icu.util.CodePointTrie.Data data
      Deprecated.
      This API is ICU internal only.
    • dataLength

      @Deprecated protected final int dataLength
      Deprecated.
      This API is ICU internal only.
    • highStart

      @Deprecated protected final int highStart
      Deprecated.
      This API is ICU internal only.
      Start of the last range which ends at U+10FFFF.
  • Method Details

    • fromBinary

      public static CodePointTrie fromBinary(CodePointTrie.Type type, CodePointTrie.ValueWidth valueWidth, ByteBuffer bytes)
      Creates a trie from its binary form, stored in the ByteBuffer starting at the current position. Advances the buffer position to just after the trie data. Inverse of toBinary(OutputStream).

      The data is copied from the buffer; later modification of the buffer will not affect the trie.

      Parameters:
      type - selects the trie type; this method throws an exception if the type does not match the binary data; use null to accept any type
      valueWidth - selects the number of bits in a data value; this method throws an exception if the valueWidth does not match the binary data; use null to accept any data value width
      bytes - a buffer containing the binary data of a CodePointTrie
      Returns:
      the trie
      See Also:
    • getType

      public abstract CodePointTrie.Type getType()
      Returns the trie type.
      Returns:
      the trie type
    • getValueWidth

      public final CodePointTrie.ValueWidth getValueWidth()
      Returns the number of bits in a trie data value.
      Returns:
      the number of bits in a trie data value
    • get

      public int get(int c)
      Returns the value for a code point as stored in the map, with range checking. Returns an implementation-defined error value if c is not in the range 0..U+10FFFF.
      Specified by:
      get in class CodePointMap
      Parameters:
      c - the code point
      Returns:
      the map value, or an implementation-defined error value if the code point is not in the range 0..U+10FFFF
    • asciiGet

      public final int asciiGet(int c)
      Returns a trie value for an ASCII code point, without range checking.
      Parameters:
      c - the input code point; must be U+0000..U+007F
      Returns:
      The ASCII code point's trie value.
    • getRange

      public final boolean getRange(int start, CodePointMap.ValueFilter filter, CodePointMap.Range range)
      Sets the range object to a range of code points beginning with the start parameter. The range start is the same as the start input parameter (even if there are preceding code points that have the same value). The range end is the last code point such that all those from start to there have the same value. Returns false if start is not 0..U+10FFFF. Can be used to efficiently iterate over all same-value ranges in a map. (This is normally faster than iterating over code points and get()ting each value, but may be much slower than a data structure that stores ranges directly.)

      If the CodePointMap.ValueFilter parameter is not null, then the value to be delivered is passed through that filter, and the return value is the end of the range where all values are modified to the same actual value. The value is unchanged if that parameter is null.

      Example:

       int start = 0;
       CodePointMap.Range range = new CodePointMap.Range();
       while (map.getRange(start, null, range)) {
           int end = range.getEnd();
           int value = range.getValue();
           // Work with the range start..end and its value.
           start = end + 1;
       }
       
      Specified by:
      getRange in class CodePointMap
      Parameters:
      start - range start
      filter - an object that may modify the map data value, or null if the values from the map are to be used unmodified
      range - the range object that will be set to the code point range and value
      Returns:
      true if start is 0..U+10FFFF; otherwise no new range is fetched
    • toBinary

      public final int toBinary(OutputStream os)
      Parameters:
      os - the output stream
      Returns:
      the number of bytes written
    • fastIndex

      @Deprecated protected final int fastIndex(int c)
      Deprecated.
      This API is ICU internal only.
    • smallIndex

      @Deprecated protected final int smallIndex(CodePointTrie.Type type, int c)
      Deprecated.
      This API is ICU internal only.
    • cpIndex

      @Deprecated protected abstract int cpIndex(int c)
      Deprecated.
      This API is ICU internal only.