I am new to SableCC. Just ran the calculator example at http://sablecc.sourceforge.net/thesis/thesis.html#PAGE26. I used the grammar file and interpreter file as they are, and tried to parse simple arithmetic expression like "45 * 5 + 2". The problem is, the interpreter method caseAMultFactor does not seem to be hit. I see it hit caseAPlusExpr, or caseAMinusExpr if I change the "+" to "-". So does the Start.apply(DepthFirstAdapter) method only go through the top mode node? How can I iterate through all nodes like that sample codes seem to do? I am using Java 1.7 and hope that's not a problem.
For your convenience I have pasted the grammar and interpreter codes here. Thanks for your help.
### Grammar:
Package postfix;
Tokens
number = ['0' .. '9']+;
plus = '+';
minus = '-';
mult = '*';
div = '/';
mod = '%';
l_par = '(';
r_par = ')';
blank = (' ' | 13 | 10)+;
Ignored Tokens
blank;
Productions
expr =
{factor} factor |
{plus} expr plus factor |
{minus} expr minus factor;
factor =
{term} term |
{mult} factor mult term |
{div} factor div term |
{mod} factor mod term;
term =
{number} number |
{expr} l_par expr r_par;
### Interpreter:
package postfix.interpret;
import postfix.analysis.DepthFirstAdapter;
import postfix.node.ADivFactor;
import postfix.node.AMinusExpr;
import postfix.node.AModFactor;
import postfix.node.AMultFactor;
import postfix.node.APlusExpr;
import postfix.node.TNumber;
public class Interpreter extends DepthFirstAdapter
{
public void caseTNumber(TNumber node)
{// When we see a number, we print it.
System.out.print(node);
}
public void caseAPlusExpr(APlusExpr node)
{
System.out.println(node);
}
public void caseAMinusExpr(AMinusExpr node)
{
System.out.println(node);
}
public void caseAMultFactor(AMultFactor node)
{// out of alternative {mult} in Factor, we print the mult.
System.out.print(node.getMult());
}
public void outAMultFactor(AMultFactor node)
{// out of alternative {mult} in Factor, we print the mult.
System.out.print(node.getMult());
}
public void outADivFactor(ADivFactor node)
{// out of alternative {div} in Factor, we print the div.
System.out.print(node.getDiv());
}
public void outAModFactor(AModFactor node)
{// out of alternative {mod} in Factor, we print the mod.
System.out.print(node.getMod());
}
}