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Posted to dev@vxquery.apache.org by Riyafa Abdul Hameed <ri...@cse.mrt.ac.lk> on 2016/07/27 11:46:58 UTC
Implementing libjn:accumulate
Hi,
I have attempted to implement libjn:accumulate[1]. This implementation is
based on the part of the specification[2] which states that the function be
implemented as follows:
declare function libjn:accumulate($sequence as item()*) as object()
{
{|
for $key in $sequence() return { $key : $sequence($key) }
|}
};
Since this method uses the dynamic constructor for objects this will throw
an error upon pair collision.
But the specification also says :
"This function dynamically builds an object, like jn:object, except that it
does not throw an error upon pair collision. Instead, it accumulates them
into an array."
I am not sure I understand this because this conflicts with the previous
(declare function) method specified and my implementation is based on the
declare function method. What is the use of accumulating them into an
array? Further no examples are provided on this.
[1] https://github.com/apache/vxquery/pull/126
[2]
http://jsoniq.org/docs/JSONiqExtensionToXQuery/html-single/index.html#idm139680684849856
Thank you.
Yours sincerely,
Riyafa
--
Riyafa Abdul Hameed
Undergraduate, University of Moratuwa
Email: riyafa.12@cse.mrt.ac.lk
Website: https://riyafa.wordpress.com/ <http://riyafa.wordpress.com/>
<http://facebook.com/riyafa.ahf> <http://lk.linkedin.com/in/riyafa>
<http://twitter.com/Riyafa1>
Re: Implementing libjn:accumulate
Posted by Riyafa Abdul Hameed <ri...@cse.mrt.ac.lk>.
Hi Till,
Regarding the comment on the PR[1]:
The fact that libjn:accumulate(({ "a": { "c": "d" } }, { "a": { "c": "d" }
})) returns {"a":{"c":"d"}} because since the specification for
libjn:accumulate was not clear, I thought that it would behave similar to
libjn:intersect and hence added a check to remove duplicate values for the
same key when accumulating into an array. So one { "c": "d" } is removed
because it's a duplicate value.
You can test with an entry like libjn:accumulate(({ "a": { "c": "d" } }, {
"a": { "e": "f" } })) which would return {"a":[{"c":"d"},{"e":"f"}]}. I
have also added this test case to the PR[1].
[1] https://github.com/apache/vxquery/pull/126
Thank you.
Yours sincerely,
Riyafa
On 28 July 2016 at 08:49, Riyafa Abdul Hameed <ri...@cse.mrt.ac.lk>
wrote:
> Hi,
>
> I have updated the PR[1] to fit the specification on creating an array.
>
> [1] https://github.com/apache/vxquery/pull/126
>
> Thank you.
>
> Yours sincerely,
> Riyafa
>
> On 27 July 2016 at 21:11, Riyafa Abdul Hameed <ri...@cse.mrt.ac.lk>
> wrote:
>
>> Hi Till,
>>
>> That's helpful. Thank you.
>>
>> Yours sincerely,
>> Riyafa
>>
>> On 27 July 2016 at 21:03, Till Westmann <ti...@apache.org> wrote:
>>
>>> Hi Riyafa,
>>>
>>> the description is a spec is indeed a little terse :)
>>>
>>> Examples are:
>>>
>>> accumulate(({ "a": "b" }, { "c": "d" })) returns { "a": "b", "c": "d" }
>>>
>>> accumulate(({ "a": "b" }, { "a": "d" })) returns { "a": [ "b", "d" ] }
>>>
>>> In the second example there is a collision for the key "a" and instead of
>>> raising an error, the function will create an array that contain all the
>>> values for the key "a" in the source objects and use that as the value
>>> for "a" in the result object.
>>>
>>> Does this make sense?
>>>
>>> Cheers,
>>> Till
>>>
>>>
>>> On 27 Jul 2016, at 4:46, Riyafa Abdul Hameed wrote:
>>>
>>> Hi,
>>>>
>>>> I have attempted to implement libjn:accumulate[1]. This implementation
>>>> is
>>>> based on the part of the specification[2] which states that the
>>>> function be
>>>> implemented as follows:
>>>>
>>>> declare function libjn:accumulate($sequence as item()*) as object()
>>>> {
>>>> {|
>>>> for $key in $sequence() return { $key : $sequence($key) }
>>>> |}
>>>> };
>>>>
>>>> Since this method uses the dynamic constructor for objects this will
>>>> throw
>>>> an error upon pair collision.
>>>> But the specification also says :
>>>> "This function dynamically builds an object, like jn:object, except
>>>> that it
>>>> does not throw an error upon pair collision. Instead, it accumulates
>>>> them
>>>> into an array."
>>>>
>>>> I am not sure I understand this because this conflicts with the previous
>>>> (declare function) method specified and my implementation is based on
>>>> the
>>>> declare function method. What is the use of accumulating them into an
>>>> array? Further no examples are provided on this.
>>>>
>>>> [1] https://github.com/apache/vxquery/pull/126
>>>> [2]
>>>>
>>>> http://jsoniq.org/docs/JSONiqExtensionToXQuery/html-single/index.html#idm139680684849856
>>>>
>>>> Thank you.
>>>>
>>>> Yours sincerely,
>>>> Riyafa
>>>> --
>>>> Riyafa Abdul Hameed
>>>> Undergraduate, University of Moratuwa
>>>>
>>>> Email: riyafa.12@cse.mrt.ac.lk
>>>> Website: https://riyafa.wordpress.com/ <http://riyafa.wordpress.com/>
>>>> <http://facebook.com/riyafa.ahf> <http://lk.linkedin.com/in/riyafa>
>>>> <http://twitter.com/Riyafa1>
>>>>
>>>
>>
>>
>> --
>> Riyafa Abdul Hameed
>> Undergraduate, University of Moratuwa
>>
>> Email: riyafa.12@cse.mrt.ac.lk
>> Website: https://riyafa.wordpress.com/ <http://riyafa.wordpress.com/>
>> <http://facebook.com/riyafa.ahf> <http://lk.linkedin.com/in/riyafa>
>> <http://twitter.com/Riyafa1>
>>
>
>
>
> --
> Riyafa Abdul Hameed
> Undergraduate, University of Moratuwa
>
> Email: riyafa.12@cse.mrt.ac.lk
> Website: https://riyafa.wordpress.com/ <http://riyafa.wordpress.com/>
> <http://facebook.com/riyafa.ahf> <http://lk.linkedin.com/in/riyafa>
> <http://twitter.com/Riyafa1>
>
--
Riyafa Abdul Hameed
Undergraduate, University of Moratuwa
Email: riyafa.12@cse.mrt.ac.lk
Website: https://riyafa.wordpress.com/ <http://riyafa.wordpress.com/>
<http://facebook.com/riyafa.ahf> <http://lk.linkedin.com/in/riyafa>
<http://twitter.com/Riyafa1>
Re: Implementing libjn:accumulate
Posted by Riyafa Abdul Hameed <ri...@cse.mrt.ac.lk>.
Hi,
I have updated the PR[1] to fit the specification on creating an array.
[1] https://github.com/apache/vxquery/pull/126
Thank you.
Yours sincerely,
Riyafa
On 27 July 2016 at 21:11, Riyafa Abdul Hameed <ri...@cse.mrt.ac.lk>
wrote:
> Hi Till,
>
> That's helpful. Thank you.
>
> Yours sincerely,
> Riyafa
>
> On 27 July 2016 at 21:03, Till Westmann <ti...@apache.org> wrote:
>
>> Hi Riyafa,
>>
>> the description is a spec is indeed a little terse :)
>>
>> Examples are:
>>
>> accumulate(({ "a": "b" }, { "c": "d" })) returns { "a": "b", "c": "d" }
>>
>> accumulate(({ "a": "b" }, { "a": "d" })) returns { "a": [ "b", "d" ] }
>>
>> In the second example there is a collision for the key "a" and instead of
>> raising an error, the function will create an array that contain all the
>> values for the key "a" in the source objects and use that as the value
>> for "a" in the result object.
>>
>> Does this make sense?
>>
>> Cheers,
>> Till
>>
>>
>> On 27 Jul 2016, at 4:46, Riyafa Abdul Hameed wrote:
>>
>> Hi,
>>>
>>> I have attempted to implement libjn:accumulate[1]. This implementation is
>>> based on the part of the specification[2] which states that the function
>>> be
>>> implemented as follows:
>>>
>>> declare function libjn:accumulate($sequence as item()*) as object()
>>> {
>>> {|
>>> for $key in $sequence() return { $key : $sequence($key) }
>>> |}
>>> };
>>>
>>> Since this method uses the dynamic constructor for objects this will
>>> throw
>>> an error upon pair collision.
>>> But the specification also says :
>>> "This function dynamically builds an object, like jn:object, except that
>>> it
>>> does not throw an error upon pair collision. Instead, it accumulates them
>>> into an array."
>>>
>>> I am not sure I understand this because this conflicts with the previous
>>> (declare function) method specified and my implementation is based on the
>>> declare function method. What is the use of accumulating them into an
>>> array? Further no examples are provided on this.
>>>
>>> [1] https://github.com/apache/vxquery/pull/126
>>> [2]
>>>
>>> http://jsoniq.org/docs/JSONiqExtensionToXQuery/html-single/index.html#idm139680684849856
>>>
>>> Thank you.
>>>
>>> Yours sincerely,
>>> Riyafa
>>> --
>>> Riyafa Abdul Hameed
>>> Undergraduate, University of Moratuwa
>>>
>>> Email: riyafa.12@cse.mrt.ac.lk
>>> Website: https://riyafa.wordpress.com/ <http://riyafa.wordpress.com/>
>>> <http://facebook.com/riyafa.ahf> <http://lk.linkedin.com/in/riyafa>
>>> <http://twitter.com/Riyafa1>
>>>
>>
>
>
> --
> Riyafa Abdul Hameed
> Undergraduate, University of Moratuwa
>
> Email: riyafa.12@cse.mrt.ac.lk
> Website: https://riyafa.wordpress.com/ <http://riyafa.wordpress.com/>
> <http://facebook.com/riyafa.ahf> <http://lk.linkedin.com/in/riyafa>
> <http://twitter.com/Riyafa1>
>
--
Riyafa Abdul Hameed
Undergraduate, University of Moratuwa
Email: riyafa.12@cse.mrt.ac.lk
Website: https://riyafa.wordpress.com/ <http://riyafa.wordpress.com/>
<http://facebook.com/riyafa.ahf> <http://lk.linkedin.com/in/riyafa>
<http://twitter.com/Riyafa1>
Re: Implementing libjn:accumulate
Posted by Riyafa Abdul Hameed <ri...@cse.mrt.ac.lk>.
Hi Till,
That's helpful. Thank you.
Yours sincerely,
Riyafa
On 27 July 2016 at 21:03, Till Westmann <ti...@apache.org> wrote:
> Hi Riyafa,
>
> the description is a spec is indeed a little terse :)
>
> Examples are:
>
> accumulate(({ "a": "b" }, { "c": "d" })) returns { "a": "b", "c": "d" }
>
> accumulate(({ "a": "b" }, { "a": "d" })) returns { "a": [ "b", "d" ] }
>
> In the second example there is a collision for the key "a" and instead of
> raising an error, the function will create an array that contain all the
> values for the key "a" in the source objects and use that as the value
> for "a" in the result object.
>
> Does this make sense?
>
> Cheers,
> Till
>
>
> On 27 Jul 2016, at 4:46, Riyafa Abdul Hameed wrote:
>
> Hi,
>>
>> I have attempted to implement libjn:accumulate[1]. This implementation is
>> based on the part of the specification[2] which states that the function
>> be
>> implemented as follows:
>>
>> declare function libjn:accumulate($sequence as item()*) as object()
>> {
>> {|
>> for $key in $sequence() return { $key : $sequence($key) }
>> |}
>> };
>>
>> Since this method uses the dynamic constructor for objects this will throw
>> an error upon pair collision.
>> But the specification also says :
>> "This function dynamically builds an object, like jn:object, except that
>> it
>> does not throw an error upon pair collision. Instead, it accumulates them
>> into an array."
>>
>> I am not sure I understand this because this conflicts with the previous
>> (declare function) method specified and my implementation is based on the
>> declare function method. What is the use of accumulating them into an
>> array? Further no examples are provided on this.
>>
>> [1] https://github.com/apache/vxquery/pull/126
>> [2]
>>
>> http://jsoniq.org/docs/JSONiqExtensionToXQuery/html-single/index.html#idm139680684849856
>>
>> Thank you.
>>
>> Yours sincerely,
>> Riyafa
>> --
>> Riyafa Abdul Hameed
>> Undergraduate, University of Moratuwa
>>
>> Email: riyafa.12@cse.mrt.ac.lk
>> Website: https://riyafa.wordpress.com/ <http://riyafa.wordpress.com/>
>> <http://facebook.com/riyafa.ahf> <http://lk.linkedin.com/in/riyafa>
>> <http://twitter.com/Riyafa1>
>>
>
--
Riyafa Abdul Hameed
Undergraduate, University of Moratuwa
Email: riyafa.12@cse.mrt.ac.lk
Website: https://riyafa.wordpress.com/ <http://riyafa.wordpress.com/>
<http://facebook.com/riyafa.ahf> <http://lk.linkedin.com/in/riyafa>
<http://twitter.com/Riyafa1>
Re: Implementing libjn:accumulate
Posted by Till Westmann <ti...@apache.org>.
Hi Riyafa,
the description is a spec is indeed a little terse :)
Examples are:
accumulate(({ "a": "b" }, { "c": "d" })) returns { "a": "b", "c": "d" }
accumulate(({ "a": "b" }, { "a": "d" })) returns { "a": [ "b", "d" ] }
In the second example there is a collision for the key "a" and instead
of
raising an error, the function will create an array that contain all the
values for the key "a" in the source objects and use that as the value
for "a" in the result object.
Does this make sense?
Cheers,
Till
On 27 Jul 2016, at 4:46, Riyafa Abdul Hameed wrote:
> Hi,
>
> I have attempted to implement libjn:accumulate[1]. This implementation
> is
> based on the part of the specification[2] which states that the
> function be
> implemented as follows:
>
> declare function libjn:accumulate($sequence as item()*) as object()
> {
> {|
> for $key in $sequence() return { $key : $sequence($key) }
> |}
> };
>
> Since this method uses the dynamic constructor for objects this will
> throw
> an error upon pair collision.
> But the specification also says :
> "This function dynamically builds an object, like jn:object, except
> that it
> does not throw an error upon pair collision. Instead, it accumulates
> them
> into an array."
>
> I am not sure I understand this because this conflicts with the
> previous
> (declare function) method specified and my implementation is based on
> the
> declare function method. What is the use of accumulating them into an
> array? Further no examples are provided on this.
>
> [1] https://github.com/apache/vxquery/pull/126
> [2]
> http://jsoniq.org/docs/JSONiqExtensionToXQuery/html-single/index.html#idm139680684849856
>
> Thank you.
>
> Yours sincerely,
> Riyafa
> --
> Riyafa Abdul Hameed
> Undergraduate, University of Moratuwa
>
> Email: riyafa.12@cse.mrt.ac.lk
> Website: https://riyafa.wordpress.com/ <http://riyafa.wordpress.com/>
> <http://facebook.com/riyafa.ahf> <http://lk.linkedin.com/in/riyafa>
> <http://twitter.com/Riyafa1>