AST_ParList.java

import java.util.*;
import Jakarta.util.FixDosOutputStream;
import java.io.*;

//------------- extracting parameters from parameter list -----
//------------- this really is a common utility and should be
//------------- placed in its own layer for others to use
//------------- originally written for Unpack tool

public class AST_ParList {

    public String onlyParams() {
        AstCursor c = new  AstCursor();
        String result = "";

        for ( c.FirstElement( this ); c.MoreElement(); c.NextElement() ) {
            // here's what I'm taking advantage of -- I know
            // a formal parameter will always be a FormParDecl production
            // and that a VariableDeclaratorId will always be a
            // DecNameDim production.  To generalize, it is necessary
            // to push a set of abstract methods through a set of classes...

            FormParDecl fpd = ( FormParDecl ) c.node;
            DecNameDim  dnd = ( DecNameDim ) fpd.arg[1];

            String varname = dnd.arg[0].tok[0].tokenName();
            if ( result.equals( "" ) )
                result = varname;
            else
                result = result + ", " + varname;
        }
        return result;
    }

    public Vector onlyTypes() {
        AstCursor c = new  AstCursor();
        Vector v = new Vector();
         
        for ( c.FirstElement( this ); c.MoreElement(); c.NextElement() ) {
            FormParDecl fpd = ( FormParDecl ) c.node;
            v.add( ( ( AST_TypeName ) fpd.arg[0] ).GetName() );
        }

        return v;
    }

    public String Signature() {
	     String sig = "";
	     AstCursor c = new AstCursor();
		  for (c.FirstElement(this); c.MoreElement(); c.NextElement()) {
		     if (c.node instanceof FormParDecl) {
			     String typeSig = ((AST_TypeName) c.node.arg[0]).Signature();
				  String varSig  = ((DecNameDim) c.node.arg[1]).Signature();
              if (!(sig.equals("")))
				     sig = sig + ",";
				  sig = sig + typeSig + varSig;
			  }
			  else 
			     AstNode.fatalError(
				     "can't produce signature of a variable declaration");
		  }
		  return sig;
	}
}