// param.beh -- Parameterization expansion
// $Id: param.beh,v 1.1 1998/03/11 22:28:06 dougo Exp $

Program {
  /** Replace all parameterized classes by expanding the
      corresponding definition and replacing the parameters. */
  private void expandParamDefs() to ClassSpec {
    after ClassSpec (@
      ClassName name = host.get_classname();
      ClassSpec_Commalist actuals = host.get_actual_parameters();
      if (actuals != null) {
	// It's a parameterized class; make sure it hasn't already been
	// defined.
	ClassName newname = host.expandName();
	if (!Program.prog.definesClass(newname)) {
	  // It hasn't; get the parameterized definition, copy it,
	  // replace the parameters with the actual parameters, and add
	  // it to the list of class defs.
	  ClassDef paramdef = Program.prog.findClassDef(name);
	  if (paramdef == null) {
	    System.err.println("Error: no such parameterized class \""
				+ name + "\"");
	  } else {
	    ClassDef actualdef = paramdef.deepCopy();
	    ParamClassName pname = ParamClassName.parse(newname.toString());
	    actualdef.set_paramclassname(pname);
	    actualdef.replaceParams(paramdef.get_parameters(), actuals);
	    Program.prog.addClassDef(actualdef);
	  }
	}
      }
    @)
    after Program (@
      host.removeParamDefs();
    @)
  }
  // Remove the parameterized definitions from the class graph.
  void removeParamDefs() to { ClassGraphEntry, ClassDef } {
    (@ ClassGraph cg = new ClassGraph(); @)
    before ClassGraphEntry (@
      if (!(host instanceof ClassDef)) cg.addClassGraphEntry(host);
    @)
    before ClassDef (@
      if (host.get_parameters() == null) cg.addClassDef(host);
    @)
    after Program (@
      host.set_cg(cg);
    @)
  }
}

ClassSpec {
  /** Concatenate the parameters with "_" in front of the classname.
      Assumes the parameters have already been expanded.
      Mutates classname and actual_parameters. */
  ClassName expandName() (@
    if (actual_parameters != null) {
      String newname = actual_parameters.concatenateNames() + classname;
      classname = ClassName.parse(newname);
      actual_parameters = null;
    }
    return classname;
  @)
}

ClassSpec_Commalist {
  String concatenateNames() to ClassName {
    init (@ return_val = ""; @)
    before ClassName (@ return_val += host + "_"; @)
  }
}

ClassDef {
  void replaceParams(ClassName_Commalist params, ClassSpec_Commalist actuals)
    = allParts
  {
    before { Part, RepeatedPart } (@
      int i = params.indexOf(host.get_classname());
      if (i != -1) {
	ClassSpec actual = actuals.elementAt(i);
	host.set_classname(actual.get_classname());
      }
    @)
  }
}