gnu.regexp
Interface CharIndexed


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.


Field Summary
static 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.
 
Method Summary
 char charAt(int index)
          Returns the character at the given offset past the current cursor position in the input.
 boolean isValid()
          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 Detail

OUT_OF_BOUNDS

public 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.
Method Detail

charAt

public 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.

move

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

isValid

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