Package gnu.regexp

Interface CharIndexed

All Known Implementing Classes:
CharIndexedCharArray, CharIndexedInputStream, CharIndexedReader, CharIndexedString, CharIndexedStringBuffer

public interface CharIndexed
Defines the interface used internally so that different types of source text can be accessed in the same way. Built-in concrete classes provide support for String, StringBuffer, InputStream and char[] types. A class that is CharIndexed supports the notion of a cursor within a block of text. The cursor must be able to be advanced via the move() method. The charAt() method returns the character at the cursor position plus a given offset.
Author:
Wes Biggs
  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final char
    Defines a constant (0xFFFF was somewhat arbitrarily chosen) that can be returned by the charAt() function indicating that the specified index is out of range.
  • Method Summary

    Modifier and Type
    Method
    Description
    char
    charAt(int index)
    Returns the character at the given offset past the current cursor position in the input.
    boolean
    Returns true if the most recent move() operation placed the cursor position at a valid position in the input.
    boolean
    move(int index)
    Shifts the input buffer by a given number of positions.
  • Field Details

    • OUT_OF_BOUNDS

      static final char OUT_OF_BOUNDS
      Defines a constant (0xFFFF was somewhat arbitrarily chosen) that can be returned by the charAt() function indicating that the specified index is out of range.
      See Also:
  • Method Details

    • charAt

      char charAt(int index)
      Returns the character at the given offset past the current cursor position in the input. The index of the current position is zero. It is possible for this method to be called with a negative index. This happens when using the '^' operator in multiline matching mode or the '\b' or '\<' word boundary operators. In any case, the lower bound is currently fixed at -2 (for '^' with a two-character newline).
      Parameters:
      index - the offset position in the character field to examine
      Returns:
      the character at the specified index, or the OUT_OF_BOUNDS character defined by this interface.
    • move

      boolean move(int index)
      Shifts the input buffer by a given number of positions. Returns true if the new cursor position is valid.
    • isValid

      boolean isValid()
      Returns true if the most recent move() operation placed the cursor position at a valid position in the input.