Hi,
Catching up on this.
This seems useful:
Stream<MatchResult> Pattern.matchAsStream(...)
MatchResult stream elements need to be cloned via Matcher.toMatchResult.
The following is perhaps less useful though might be handy for some matcher
updates before handing off to a stream:
Stream<MatchResult> Pattern.match(...).stream()
The stream source implementation will need to check for co-omodification of the
matcher.
I still think we need some point lamdification though because the
Matcher.append* methods are stateful and don't play nicely with streams. So
something like:
String Matcher.replace(Function<MatchResult, String> f)
is also useful (this was previously discussed a while back on lambda-dev).
Paul.
On Nov 20, 2014, at 12:10 AM, Remi Forax <fo...@univ-mlv.fr> wrote:
>
> On 11/19/2014 10:54 PM, Dan Smith wrote:
>> Working with the pattern matching API, I noticed that it could be made a lot
>> less clumsy with some lambdafication.
>>
>> Here's the status quo:
>>
>> Pattern p = Pattern.compile("(\w)*, (\d)*, (\w)*");
>> for (String s : lines) {
>> Matcher m = p.matcher(str);
>> if (m.match(s)) {
>> System.out.println(m.group(1));
>> }
>> }
>>
>> With a lambda-friendly API:
>>
>> Pattern p = Pattern.compile("\d*, \d*, \d*");
>> for (String s : lines) {
>> p.match(str, r -> System.out.println(r.group(1)));
>> }
>>
>> The 'match' is declared as 'match(String, Consumer<MatchResult>)'. You
>> could argue that the functional interface should be a Function rather than a
>> Consumer; whatever.
>>
>> Could also do 'matchFirst', 'matchAll' -- the latter eliminates even more
>> boilerplate.
>>
>> If considered useful, this could be added to String too:
>>
>> str.match("\d*, \d*, \d*", r -> System.out.println(r.group(1)));
>>
>> Is this something that has been considered? Should I file an RFE?
>>
>> —Dan
>
> While I agree that we could have a more lambda-ish API,
> I prefer having a method Pattern.matchAsStream that returns a Stream of
> MatchResult
> because its more flexible that the API you propose.
> It's also more coherent with the fact that there is already a method
> splitAsStream().
>
> Pattern p = Pattern.compile("(\d)*, (\d)*, (\d)*");
> for (String s : lines) {
> p.matchAsStream(line).forEach(r -> System.out.println(r.group(1)));
> }
>
>
> or written using flatMap()
>
> Pattern p = Pattern.compile("(\d)*, (\d)*, (\d)*");
> lines.stream().flatMap(line -> p.matchAsStream(line)).map(r ->
> r.group(1)).forEach(System.out::println);
>
>
> and yes, please log a RFE.
>
> Rémi
>
>
>
>
