persistence.antlr.ParseTree 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
*/
import persistence.antlr.*;
import persistence.antlr.collections.AST;
public abstract class ParseTree extends BaseAST {
/** Walk parse tree and return requested number of derivation steps.
* If steps <= 0, return node text. If steps == 1, return derivation
* string at step.
*/
public String getLeftmostDerivationStep(int step) {
if ( step<=0 ) {
return toString();
}
StringBuffer buf = new StringBuffer(2000);
getLeftmostDerivation(buf, step);
return buf.toString();
}
public String getLeftmostDerivation(int maxSteps) {
StringBuffer buf = new StringBuffer(2000);
buf.append(" "+this.toString());
buf.append("\n");
for (int d=1; d");
buf.append(getLeftmostDerivationStep(d));
buf.append("\n");
}
return buf.toString();
}
/** Get derivation and return how many you did (less than requested for
* subtree roots.
*/
protected abstract int getLeftmostDerivation(StringBuffer buf, int step);
// just satisfy BaseAST interface; unused as we manually create nodes
public void initialize(int i, String s) {
}
public void initialize(AST ast) {
}
public void initialize(Token token) {
}
}