Pattern.splitAsStream/asPredicate

[Paul Sandoz]

On Apr 24, 2013, at 7:16 PM, Remi Forax <forax at univ-mlv.fr> wrote:

> On 04/22/2013 06:09 PM, Paul Sandoz wrote:
>> Hi,
>> 
>> It seems useful to provide an ability to create a stream from matches of a pattern, plus as a bonus create a predicate for matches of a pattern.
>> 
>> See below for more details:
>> 
>>   http://cr.openjdk.java.net/~psandoz/lambda/jdk-8012646/webrev/
>> 
>> Thoughts?
>> 
>> Paul.
>> 
> 
> Hi Paul,
> MatcherIterator should not be a local class of splitAsStream,
> because the reference to the current Pattern will be kept
> even if the Matcher not reference if anymore
> (note that the current implementation of the Matcher always references
> the Pattern object but maybe at some point the automata will be
> transformed to bytecode as by example V8 does).

Matcher returns it too:

    /**
     * Returns the pattern that is interpreted by this matcher.
     *
     * @return  The pattern for which this matcher was created
     */
    public Pattern pattern() {


> To summarize, the class MatcherIterator defines 4 fields instead of 3.
> 

Yes, it's an inner class, but  I prefer the locality, since splitAsStream is the only method that uses the class.


> The is no need to initialize current and nextElement to their default values,
> javac emits bytecodes for that.
> 
> in next(), the else is useless and it's rare in the jdk sources to find a else after a throw.
> in hasNext(), you can re-order the branch of the first test to avoid the code to be shifted to the right.
>   if (nextElement != null) {
>     return true;
>   }
>   if (current == input.length()) {
>     ...
> 

Thanks i have cleaned up that code.

Paul.


> and yes, this method is useful :)
> 
> cheers,
> Rémi
> 
> 
> 
> 
>