Struggling with Valhalla conversion of library

[Srikanth]

Thanks for the test case, I am looking into this one...

(same problem as reported by another EA tester: Ben Evans)

Srikanth.

On 17/08/19 8:35 PM, Philippe Marschall wrote:
> Hello Srikanth
>
> I was able to retest with the tip of the lworld branch. I can confirm
> the lambda issue, the first issue, is gone.
>
> As for the second issue I was able to extract this minimal reproducer
>
> interface Sample<K extends Comparable<? super K>, V> {
>
>   void doesCompile(InlineType<? extends K> argument);
>
>   void doesNotCompile(java.util.Map.Entry<InlineType<? extends K>, ?
> extends V> argument);
>
> }
>
> inline class InlineType<E> {
>
>   private E element;
>
>   InlineType(E element) {
>     this.element = element;
>   }
>
> }
>
> The method #doesCompile doe compile but the method #doesNotCompile does
> not compile and instead I get the following error:
>
> error: unexpected type
>   void doesNotCompile(java.util.Map.Entry<InlineType<? extends K>, ?
> extends V> argument);
>                                                     ^
>   required: reference
>   found:    InlineType<? extends K>
>   where K is a type-variable:
>     K extends Comparable<? super K> declared in interface Sample
>
>
> Cheers
> Philippe
>
> On 14.08.19 12:51, Srikanth wrote:
>> Hello Philippe,
>>
>> There has been a further defect fix
>> https://bugs.openjdk.java.net/browse/JDK-8229700 that should also help
>> you. If you are able to test the tip of valhalla repo lworld branch,
>> that is great!
>>
>> If not, I am told this Friday there will a refresh of the EA bits. That
>> should simplify testing for those that don't want to work with source
>> forests.
>>
>> Could you in any case please see if you are able to extract test cases
>> and send them inline in mail ?
>> That would greatly speed up the turn around time for any remaining
>> problems.
>>
>> Appreciate your testing and the defect reports!
>> Srikanth
>>
>> On 14/08/19 2:39 PM, Srikanth wrote:
>>> Hello Philippe,
>>>
>>> With the resolution of
>>> https://bugs.openjdk.java.net/browse/JDK-8229537 via the push
>>> http://hg.openjdk.java.net/valhalla/valhalla/rev/7ec951ef532d at least
>>> the first of your
>>> problems should have been fixed and the explicit lambda version viz:
>>>
>>> public static AdjacencyTester<U96?> adjacencyTester() {
>>>     return (U96? low, U96? high) -> {
>>>       // lambda body
>>>     };
>>>   }
>>>
>>> should compile.
>>>
>>> Can you check with the lworld branch tip of valhalla ?
>>>
>>> I am happy to verify this fix and also investigate a fix for the other
>>> problems you reported.
>>> But it would help if I have test cases extracted and attached to mail
>>> - is that possible ?
>>> I am not familiar with github and having a bit of a bother getting
>>> what I need from the
>>> pointers.
>>>
>>> TIA
>>> Srikanth
>>>
>>> On 05/08/19 3:14 AM, Philippe Marschall wrote:
>>>> Hi
>>>>
>>>> As you published the LW2 prototype I thought I tried to convert one of
>>>> my libraries [1] to Valhalla and see how it goes. Right now I'm
>>>> struggling with generics.
>>>>
>>>> Some context about the library. The library implements a range tree 
>>>> that
>>>> allows to map a range of keys to a single value. Eg. {[100,199] -> 
>>>> "1",
>>>> [200,299] -> "2"}. The library should support both inline and 
>>>> reference
>>>> types as keys and values.
>>>> The potential for inline classes is limited as the tree nodes are
>>>> mutable and recursive. There are however two good candidates, the 
>>>> range
>>>> class and an unsigned 96bit integer class (called U96) that is 
>>>> provided
>>>> for convenience.
>>>>
>>>> The unsigned 96bit integer class  was easy to convert. I had to change
>>>> it to implements Comparable<U96?>. I am not yet sure how I want to 
>>>> treat
>>>> null / 0.
>>>> But there are two cases where I struggled.
>>>>
>>>> First, I have an interface
>>>>
>>>> public interface AdjacencyTester<T> {
>>>>
>>>>   boolean areAdjacent(T low, T high);
>>>>
>>>> }
>>>>
>>>> I want to implement this for the unsigned 96bit integer class (called
>>>> U96). Right know in Java 8 this is implemented as
>>>>
>>>>   public static AdjacencyTester<U96> adjacencyTester() {
>>>>     return (low, high) -> {
>>>>       // lambda body
>>>>     };
>>>>   }
>>>>
>>>> Simply converting this to
>>>>
>>>>   public static AdjacencyTester<U96?> adjacencyTester() {
>>>>     return (low, high) -> {
>>>>       // lambda body
>>>>     };
>>>>   }
>>>>
>>>> did not work, I got
>>>>
>>>> com/github/marschall/rangetree/key/U96.java:[51,12] incompatible 
>>>> types:
>>>> incompatible parameter types in lambda expression
>>>>
>>>> Converting it to an anonymous inner class worked
>>>>
>>>>   public static AdjacencyTester<U96?> adjacencyTester() {
>>>>     return new AdjacencyTester<U96?>() {
>>>>       public boolean areAdjacent(U96? low, U96? high) {
>>>>         // method body
>>>>       }
>>>>     };
>>>>
>>>>   }
>>>>
>>>> Using U96? as types for the lambda arguments did not compile
>>>>
>>>>   public static AdjacencyTester<U96?> adjacencyTester() {
>>>>     return (U96? low, U96? high) -> {
>>>>       // lambda body
>>>>     };
>>>>   }
>>>>
>>>> Compilation failure:
>>>> /src/main/java/com/github/marschall/rangetree/key/U96.java:[51,16] ')'
>>>> expected
>>>> src/main/java/com/github/marschall/rangetree/key/U96.java:[51,21] :
>>>> expected
>>>> src/main/java/com/github/marschall/rangetree/key/U96.java:[51,32] ';'
>>>> expected
>>>>
>>>> Second I have a simple Range class which is supposed to hold both
>>>> reference and inline types. That was easy to convert but integrating
>>>> into my existing interfaces failed.
>>>>
>>>> public inline class Range<E> {
>>>>
>>>>   private E low;
>>>>   private E high;
>>>>
>>>> In my RangeMap interface I have #computeIfAbsent similar to the one 
>>>> from
>>>> Map.
>>>>
>>>> V computeIfAbsent(K key, Function<? super K, Entry<Range<? extends 
>>>> K>, ?
>>>> extends V>> mappingFunction)
>>>>
>>>> src/main/java/com/github/marschall/rangetree/RangeMap.java:[52,59]
>>>> unexpected type
>>>> [ERROR]   required: reference
>>>> [ERROR]   found: com.github.marschall.rangetree.Range<? extends K>
>>>>
>>>> I tried to switch to
>>>> Range<? extends K?>
>>>>
>>>> but that did not help.
>>>>
>>>> You can find the code and building instructions here [2]
>>>>
>>>>  [1] https://github.com/marschall/range-tree
>>>>  [2] https://github.com/marschall/range-tree/tree/valhalla
>>>>
>>>> Cheers
>>>> Philippe
>>>
>>
>>