/*
 * The JastAdd Extensible Java Compiler (http://jastadd.org) is covered
 * by the modified BSD License. You should have received a copy of the
 * modified BSD license with this compiler.
 * 
 * Copyright (c) 2005-2008, Torbjorn Ekman
 * All rights reserved.
 */

aspect VariableArityParameters {
  // 8.4.1

  /* The last formal parameter in a list is special; it may be a variable arity
  parameter, indicated by an elipsis following the type.*/
  public void VariableArityParameterDeclaration.nameCheck() {
    super.nameCheck();
    if(!variableArityValid())
      error("only the last formal paramater may be of variable arity");
  }

  eq ConstructorDecl.getParameter(int i).variableArityValid() = i == getNumParameter() - 1;
  eq MethodDecl.getParameter(int i).variableArityValid() = i == getNumParameter() - 1;
  eq CatchClause.getParameter().variableArityValid() = false;
  eq Program.getChild().variableArityValid() = false;

  inh boolean VariableArityParameterDeclaration.variableArityValid();

  /* If the last formal parameter is a variable arity parameter of type T, it is
  considered to define a formal parameter of type T[].*/
  eq VariableArityParameterDeclaration.type() = super.type().arrayType();

  /* The method is then a variable arity method. Otherwise, it is a fixed arity method.*/
  syn boolean MethodDecl.isVariableArity() = getNumParameter() == 0 ? false : getParameter(getNumParameter()-1).isVariableArity();
  syn boolean ConstructorDecl.isVariableArity() = getNumParameter() == 0 ? false : getParameter(getNumParameter()-1).isVariableArity();
  syn boolean ParameterDeclaration.isVariableArity() = false;
  eq VariableArityParameterDeclaration.isVariableArity() = true;

  syn ParameterDeclaration MethodDecl.lastParameter() = 
    getParameter(getNumParameter() - 1);
  syn boolean MethodAccess.invokesVariableArityAsArray() {
    if(!decl().isVariableArity())
      return false;
    if(arity() != decl().arity())
      return false;
    return getArg(getNumArg()-1).type().methodInvocationConversionTo(decl().lastParameter().type());
  }
  syn boolean ConstructorAccess.invokesVariableArityAsArray() {
    if(!decl().isVariableArity())
      return false;
    if(arity() != decl().arity())
      return false;
    return getArg(getNumArg()-1).type().methodInvocationConversionTo(decl().lastParameter().type());
  }
  syn boolean ClassInstanceExpr.invokesVariableArityAsArray() {
    if(!decl().isVariableArity())
      return false;
    if(arity() != decl().arity())
      return false;
    return getArg(getNumArg()-1).type().methodInvocationConversionTo(decl().lastParameter().type());
  }


  syn ParameterDeclaration ConstructorDecl.lastParameter() = 
    getParameter(getNumParameter() - 1);

  // 15.12.2

/*
A method is applicable if it is either applicable by subtyping (§15.12.2.2),
applicable by method invocation conversion (§15.12.2.3), or it is an applicable
variable arity method (§15.12.2.4).

The process of determining applicability begins by determining the potentially
applicable methods (§15.12.2.1). The remainder of the process is split into
three phases.

The first phase (§15.12.2.2) performs overload resolution without permitting
boxing or unboxing conversion, or the use of variable arity method invocation.
If no applicable method is found during this phase then processing continues to
the second phase.

The second phase (§15.12.2.3) performs overload resolution while allowing
boxing and unboxing, but still precludes the use of variable arity method
invocation. If no applicable method is found during this phase then processing
continues to the third phase.

The third phase (§15.12.2.4) allows overloading to be combined with variable
arity methods, boxing and unboxing.

Deciding whether a method is applicable will, in the case of generic methods
(§8.4.4), require that actual type arguments be determined. Actual type
arguments may be passed explicitly or implicitly. If they are passed
implicitly, they must be inferred (§15.12.2.7) from the types of the argument
expressions.

If several applicable methods have been identified during one of the three
phases of applicability testing, then the most specific one is chosen, as
specified in section §15.12.2.5. See the following subsections for details.
*/

  public void VariableArityParameterDeclaration.toString(StringBuffer s) {
    getModifiers().toString(s);
    getTypeAccess().toString(s);
    s.append(" ... " + name());
  }

}