[ nice-Bugs-749019 ] EnsureTypeProc has wrong type

Bugs item #749019, was opened at 2003-06-04 19:19
Message generated for change (Comment added) made by bonniot
You can respond by visiting: 
https://sourceforge.net/tracker/?func=detail&atid=112788&aid=749019&group_id=12788

Category: None
Group: None
>Status: Closed
>Resolution: Fixed
Priority: 5
Submitted By: Bryn Keller (xoltar)
>Assigned to: Daniel Bonniot (bonniot)
Summary: EnsureTypeProc has wrong type

Initial Comment:
Apologies for the long code sample - this code compiles
fine with the development version, but when run gives
this error:


[brk@brk brk]$ java -Dassertions=true -jar test.jar
Exception in thread "main"
nice.tools.code.EnsureTypeProc has wrong type
([Ljava.lang.Object;)
        at gnu.mapping.WrongType.make(WrongType.java:56)
        at test.fun.main(./test:90)

the line referenced in the stack trace is the
while(it.hasNext()) line.

void main(String[] args)
{
  
  let List<String> pos = ["1", "2", "3", "4"];
  let List<String> neg = ["-1", "-2", "-3", "-4"];
  let Iterator<(String,String)> it = zip(pos.iterator,
neg.iterator);
  while(it.hasNext()) {
    (String left, String right) = it.next();
  }
}

/**
 * Takes two iterators, and returns a new iterator
which yields
 * tuples made of one element from the first iterator,
and one
 * from the second.
 */
<T,U> Iterator<(T,U)> zip(Iterator<T> one, Iterator<U>
two);

<T,U>zip(one@Iterator, two@Iterator) = iterator(() => 
  {  
    if (one.hasNext() && two.hasNext()) {    
      let T oneItem = one.next;
      let U twoItem = two.next;
      return (oneItem, twoItem);
    }
    throw new NoSuchElementException();
  });

/**
 * Treat any ()->T function as an Iterator&lt;T&gt;.
The function
 * should raise NoSuchElementException if it can't
produce any
 * more elements.
 * 
 * Example:
 * <pre>
 * var byte counter = 0;

 * //A silly iterator from 0 to 9
 * let Iterator<byte> it = iterator(()=> {
 *    if (counter > 9)
 *       throw new NoSuchElementException();
 *    else
 *       return counter++;
 * }
 * </pre>
 */
<T> Iterator<T> iterator(()->T func) = new
FunctionIterator(function: func);

/**
 * Private. Used in iterator(()->T).
 */
class FunctionIterator<T> implements Iterator<T> 
{
  ()->T function;
  /* internal */ ?T current = null;

  private boolean fetch() 
    {
      try 
      {
	T val = (this.function)();
	current = val.cast();
	return true;
      } 
      catch (NoSuchElementException e) 
      {
	current = null;
	function = () => { throw new
UnsupportedOperationException(); };
	return false;
      }
  }

  hasNext() = current != null || this.fetch();

  <T>next() 
    {
      if (this.current != null || this.fetch()) 
	{
          let item = this.current;
	  if (item != null) 
	    {
	      this.current = null;
	      return item.cast();
	    }
	} 
      throw new NoSuchElementException();
    }

  remove() { throw new UnsupportedOperationException();
}      
}


----------------------------------------------------------------------

>Comment By: Daniel Bonniot (bonniot)
Date: 2003-11-27 12:58

Message:
Logged In: YES 
user_id=88952

This is now fixed in CVS and in the development compiler.
Sorry for the delay in fixing. 

----------------------------------------------------------------------

Comment By: Arjan Boeijink (arjanb)
Date: 2003-06-04 20:20

Message:
Logged In: YES 
user_id=688815

A simplification of this testcase:

<T,U> (T,U) foo(T x, U y) = (x,y); 

void main(String[] args) {
(String fst, String snd) = foo("abc","zyx");
}


----------------------------------------------------------------------

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https://sourceforge.net/tracker/?func=detail&atid=112788&aid=749019&group_id=12788


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