RFR 8225198 : Optimize regex tree for greedy quantifiers of type {N, }

[Ivan Gerasimov]

Thank you Claes and Brent for reviewing!

I'll edit the comment as suggested before pushing.

And yes, we do have a few testcases to verify this optimization in 
RegExTest.java / BMPTestCases.txt.

With kind regards,

Ivan


On 6/4/19 2:30 PM, Brent Christian wrote:
> Hi, Ivan
>
> The change looks fine.
>
> I would call this "noreg-cleanup".  Tests are needed to confirm the 
> correctness of the new code, which I imagine we already have.
>
>
> One small suggestion:
>
> src/java.base/share/classes/java/util/regex/Pattern.java
>
>
> 4271      * and unlimited maximum, for *, + and {N,} quantifiers.
>
>
> If the maximum is still MAX_REPS, I'd prefer to continue to say that 
> (rather than, "unlimited.")
>
> Thanks.
> -Brent
>
> On 6/3/19 12:54 PM, Ivan Gerasimov wrote:
>> Hello!
>>
>> When building a match-tree, the regex engine optimizes '*' and '+' 
>> greedy quantifiers by using special node of type CharPropertyGreedy.
>>
>> This later class can be used unmodified for other greedy quantifiers 
>> without the upper limit, i.e. of type '{N,}'.
>>
>> Would you please help review this simple optimization?
>>
>> BUGURL: https://bugs.openjdk.java.net/browse/JDK-8225198
>> WEBREV: http://cr.openjdk.java.net/~igerasim/8225198/00/webrev/
>>
>> (With the fix, one unused class was also removed.  This class was to 
>> implement conditionals, which were never supported by Java regexs.)
>>
>

-- 
With kind regards,
Ivan Gerasimov