Text Editor Buffer with 2 Stacks (Sedgewick Algorithms) Example

TextEditorBuffer.java

public class GapBuffer {

    private final Stack<Char> left, right; 
    private final int n; 

    public GapBuffer() {
        left = new Stack<>();
        right = new Stack<>();
        n = 0;
    }

    public GapBuffer(char[] existing) {
        this();
        for (char c : existing) {
            left.push(c);
        }
    }

    public void insert(char c) {
        left.push(c);
        n++;
    }

    public char get() {
        return left.peek();
    }

    public char delete() {
        char c = left.pop();
        n--;
        return c;
    }

    public void left(int k) {
        while (k-- > 0 && !left.empty()) {
            right.push(left.pop());
        }
    }

    public void right(int k) {
        while (k-- > 0 && !right.empty()) {
            left.push(right.pop());
        }
    }

    public int size() {
        return n;
    }
}