Re: Improved for each loop

From:
Daniel Pitts <newsgroup.spamfilter@virtualinfinity.net>
Newsgroups:
comp.lang.java.programmer
Date:
Mon, 13 Jul 2009 07:57:09 -0700
Message-ID:
<xXH6m.2442$dW5.1855@newsfe04.iad>
Roedy Green wrote:

On Sun, 12 Jul 2009 19:58:26 -0700, markspace <nospam@nowhere.com>
wrote, quoted or indirectly quoted someone who said :

  Object[] array ....
  for( int i : array.length ) {
    ....
  }


These in theory require an Iterable interface somewhere. Perhaps that
is why they left that off.

You might generalise that to also permit things like this:

for ( int i: anArray )

for ( int i: anArrayList )

for ( int i: someString )

I think those extensions are safe. If muddled them up with the
existing forms, the body of the loop would generate type errors.

Not really:

int[] anArray;
for (int i: anArray) // Oops.

List<Integer> anArrayList;
for (int i: anArrayList) // oops.

I am all in favour of short forms for common idioms. You eye can
grasp them in an instant and be sure some tiny variant is not
masquerading as a common idiom the way is so often with the standard
for.

There was one oversight in the original that logically should have
been there.

for ( char c : string )

If it makes you feel any better, In my home brew language Abundance
circa 1980, You could abbreviate those to

<<<FOR anArray ... FOR>>>
<<<FOR anArrayList ... FOR>>>


--
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