Lambdas in for-each loops

Remi Forax forax at
Wed Sep 5 06:51:45 PDT 2012

On 09/05/2012 03:26 PM, Brian Goetz wrote:
>> At such case I have a serious question - why for-each loop doesn't allow
>> to use Iterator? Why do we need only Iterable (and arrays of course) ?
>> May be it may sense to expand for-each loop itself and detach the
>> problem from lambda? it looks like we something like project Coin2.0 for
>> such things.
> This was a hot issue during the development of the foreach loop. In 
> the end, the EG decided that allowing Iterator in foreach loop was 
> potentually confusing, since as a side effect of being iterated, the 
> iterator was "drained".
Also, you can write horrible things like,
   Iterator<String> it = collection...
   for(String s: it) {   // ok, simple loop
    if (...) {
       it.remove();   // not a simple loop anymore

if you read the code, a foreach loop should always be a simple loop with 
no side effect on the iterable.


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