Latest build c572fa185d05 limitations

[Maurizio Cimadamore]

On 12/09/10 21:38, Howard Lovatt wrote:
> It is odd that Integer works and int doesn't, the programmer will expect that they are interchangeable. Even stranger is that:
>
>    il.forEach( #( int i ) {
>      if ( i<  4 ) { throw new Exception(); }
>      return i * i;
>    } );
>    
The problem here is that you are passing a lambda of the kind #(int x) 
where a Sam is expected, where the Sam declares a method accepting 
java.lang.Integer (not int). The spec is very clear in requiring the 
signature of the lambda to be override-equivalent w.r.t. the signature 
of the Sam method.

Maurizio
> Works (note argument is an int).
>
>    -- Howard Lovatt +61 419 971 263 (sent from my PDA)
>
> On 11/09/2010, at 10:22 PM, Maurizio Cimadamore<maurizio.cimadamore at oracle.com>  wrote:
>
>    
>> The problem has nothing to do with try/catch - it is caused by using 'int' as explicit type - if you replace it with Integer it works...
>>
>> Thanks for the report.
>> Maurizio
>>
>> On 11/09/10 06:18, Howard Lovatt wrote:
>>      
>>> Hi,
>>>
>>> Using my usual source:
>>>
>>>      143: final IntList11 il = new IntList11();
>>>      144: out.println( il );
>>>      145: il.forEach( #( int i ) { 2 * i } ); // No exception; no try
>>> block - needs type parameter
>>>      146: out.println( il );
>>>
>>> Gives:
>>>
>>> Exception in thread "main" java.lang.VerifyError: Bad local variable
>>> type in method lambdas.Main$9.call(Ljava/lang/Integer;)Ljava/lang/Integer;
>>> at offset 1
>>>     at lambdas.Main.exceptionTransparency(Main.java:145)
>>>     at lambdas.Main.main(Main.java:24)
>>>
>>> But:
>>>
>>>      try {
>>>        il.forEach( #( int i ) {
>>>          if ( i<   4 ) { throw new Exception(); }
>>>          return i * i;
>>>        } ); // Need to catch the checked exception!
>>>      } catch ( final Throwable notUsed ) {
>>>        out.println( "Exception caught 1" );
>>>      }
>>>      out.println( il );
>>>
>>> Works!
>>>
>>> And:
>>>
>>>    il.forEach( #( i ) { 2 * i } );
>>>
>>> Requires a try catch block (as before) and:
>>>
>>>    il.forEach( #( Integer i ) { 2 * i } );
>>>
>>> Works.
>>>
>>> Great to see such regular updates into the repository,
>>>
>>>    -- Howard.
>>>
>>>
>>>        
>>