Esempio n. 1
0
 /**
  * This method produces a new Abstraction which is the result of adding captured variables as new
  * arguments and bind it in current ns. It returns the name of the bound funciton.
  *
  * @param a
  * @param captured
  * @return a String object denoting the name given to this function
  * @throws SymbolException
  */
 private String lift(Abstraction a, Set captured) throws SymbolException {
   Abstraction abs = a;
   if (!captured.isEmpty()) {
     /* recreate abstraction adding captured variables */
     abs = new Abstraction();
     /* bind captured variables */
     Iterator it = captured.iterator();
     while (it.hasNext()) {
       LocalBinding lb = (LocalBinding) it.next();
       LocalBinding nlb = new LocalBinding(lb.getName());
       abs.bind(nlb);
     }
     /* rebind old variables */
     it = a.getBindings().values().iterator();
     while (it.hasNext()) {
       LocalBinding lb = (LocalBinding) it.next();
       LocalBinding nlb = new LocalBinding(lb.getName());
       abs.bind(nlb);
     }
     /* restore body */
     abs.setBody(a.getBody());
   }
   /*
    * bind new abstraction in ns if a is an anonymous abstraction - no class
    * name - then it is renamed lambdaXXX and bound in namespace. Else, it is
    * given a new name and a reference to this new name is stored in substMap.
    */
   String newname = "lambda" + counter++;
   ns.bind(newname, abs);
   abs.setClassName(ns.getName() + "." + newname);
   return newname;
 }
Esempio n. 2
0
 /**
  * Returns an Abstraction object resulting from lifting the given expression with captured
  * variable set. if <code>f
  * x y</code> is an expression with <code>y</code> a captured variable, then it is transformed
  * into <code>lambdaXXX
  * = \ y -> f x y</code> which can later be used to replace the original expression with <code>
  * lambdaXXX y</code>.
  *
  * @param e
  * @param captured
  * @return a String object
  * @throws SymbolException
  */
 private String lift(Expression e, Set captured) throws SymbolException {
   if (e instanceof Abstraction) return lift((Abstraction) e, captured);
   Abstraction abs = new Abstraction();
   /* bind captured variables */
   Iterator it = captured.iterator();
   while (it.hasNext()) {
     LocalBinding lb = (LocalBinding) it.next();
     LocalBinding nlb = new LocalBinding(lb.getName());
     abs.bind(nlb);
   }
   /* restore body */
   abs.setBody(e);
   String newname = "lambda" + counter++;
   ns.bind(newname, abs);
   return newname;
 }