persistence.antlr.ANTLRStringBuffer Maven / Gradle / Ivy
package persistence.antlr;
/* ANTLR Translator Generator
* Project led by Terence Parr at http://www.jGuru.com
* Software rights: http://www.antlr.org/license.html
*
*/
// Implementation of a StringBuffer-like object that does not have the
// unfortunate side-effect of creating Strings with very large buffers.
public class ANTLRStringBuffer {
protected char[] buffer = null;
protected int length = 0; // length and also where to store next char
public ANTLRStringBuffer() {
buffer = new char[50];
}
public ANTLRStringBuffer(int n) {
buffer = new char[n];
}
public final void append(char c) {
// This would normally be an "ensureCapacity" method, but inlined
// here for speed.
if (length >= buffer.length) {
// Compute a new length that is at least double old length
int newSize = buffer.length;
while (length >= newSize) {
newSize *= 2;
}
// Allocate new array and copy buffer
char[] newBuffer = new char[newSize];
for (int i = 0; i < length; i++) {
newBuffer[i] = buffer[i];
}
buffer = newBuffer;
}
buffer[length] = c;
length++;
}
public final void append(String s) {
for (int i = 0; i < s.length(); i++) {
append(s.charAt(i));
}
}
public final char charAt(int index) {
return buffer[index];
}
final public char[] getBuffer() {
return buffer;
}
public final int length() {
return length;
}
public final void setCharAt(int index, char ch) {
buffer[index] = ch;
}
public final void setLength(int newLength) {
if (newLength < length) {
length = newLength;
}
else {
while (newLength > length) {
append('\0');
}
}
}
public final String toString() {
return new String(buffer, 0, length);
}
}