BTW: Here is GroovyTranslator for Gremlin-Python.
https://gist.github.com/okram/406157b21371a540d2641f52a4208760
<https://gist.github.com/okram/406157b21371a540d2641f52a4208760>
Realize that Translator exists as a class in both Java and in Python with
identical APIs. … and will exist as such in JavaScript, Ruby, etc.
Its really not that complicated to create a Translator. The complication exists
in XXXTraversal, XXXTraversalSource, and XXXAnonymousTraversal:
https://gist.github.com/okram/fe6bdfe36b970af73b2bcb9e3cfc5e3d
<https://gist.github.com/okram/fe6bdfe36b970af73b2bcb9e3cfc5e3d>
..but that is written once and used over and over by various translators.
Moreover, that source code is generated automagically via introspection into
the Gremlin-Java API.
https://gist.github.com/okram/88f0ddbd9d0d257d1113b0740260a6b6
<https://gist.github.com/okram/88f0ddbd9d0d257d1113b0740260a6b6>
Marko.
http://markorodriguez.com
> On Jun 16, 2016, at 7:35 AM, Marko Rodriguez <[email protected]> wrote:
>
> Hello,
>
>> I think this is generally on the right track as there aren't many other
>> tracks to get this to work. Is it possible to leave open the option for a
>> language that is translating into itself (e.g. javascript to javascript) to
>> have the ability to take a non-string lambda if it is a language that is
>> capable of inspecting itself to get the string representation of its own
>> code?
>
> Yes. So with Python we can inspect the lambda. Thus, if you are in CPython
> and want to submit a Gremlin-Python traversal to GremlinServer running
> Jython, then the PythonTranslator would NOT just evaluate the lambda for a
> String, but instead would do the following — inspect the lambda for a String:
>
> >>> from dill.source import getsource
> >>> x = lambda a: a + 2
> >>> x
> <function <lambda> at 0x10bfe70c8>
> >>> getsource(x)
> 'x = lambda a: a + 2\n'
> >>>
>
> Realize that since we have decoupled the “translator” from the “language,”
> anyone can use Gremlin-Python and write their own translator. That translator
> can do as they please with each step(args). Thus, CPython->Jython can do as
> above with lambdas and introspect to get the code string during translation.
> For Gremlin-Python with GroovyTranslator, the best I have come up with is:
>
> >>> g.V().out().map(lambda: "it.get().value('name')")
> g.V().out().map({it.get().value('name')})
>
> Now, another drawback of “the best I have come up with" is that the
> translator’s target language is showing up in the host language. That is, the
> traversal above is forced to use a GroovyTranslator and thus is not portable
> to any other translator. While, if a traversal did NOT have lambdas, you
> could easily change the translator and everything would just work as expected.
>
> Take care,
> Marko.
>
> http://markorodriguez.com <http://markorodriguez.com/>
>
>
>>
>> On Thu, Jun 16, 2016 at 2:12 AM, Daniel Kuppitz <[email protected]
>> <mailto:[email protected]>> wrote:
>>
>>> I wouldn't say that I like it, cause code as a String will always be very
>>> error prone, but still, it's likely the only way to get lambdas working in
>>> all language variants. Hence: "cool".
>>>
>>> Cheers,
>>> Daniel
>>>
>>>
>>> On Thu, Jun 16, 2016 at 12:03 AM, Marko Rodriguez <[email protected]
>>> <mailto:[email protected]>>
>>> wrote:
>>>
>>>> Hi,
>>>>
>>>> What do people think of this idea:
>>>>
>>>> https://gist.github.com/okram/df6a104bde51a4f4f6f0da11f46909d5
>>>> <https://gist.github.com/okram/df6a104bde51a4f4f6f0da11f46909d5> <
>>>> https://gist.github.com/okram/df6a104bde51a4f4f6f0da11f46909d5
>>>> <https://gist.github.com/okram/df6a104bde51a4f4f6f0da11f46909d5>>
>>>>
>>>> If you pass a lambda/closure/anonymousFunction/etc. in the respective
>>>> language (during translation), it calls it to get the string
>>>> representation. … ?
>>>>
>>>> Marko.
>>>>
>>>> http://markorodriguez.com <http://markorodriguez.com/>
>>>>
>>>>
>>>>
>>>>> On Jun 15, 2016, at 10:50 AM, Marko Rodriguez <[email protected]>
>>>> wrote:
>>>>>
>>>>> Hello,
>>>>>
>>>>> I think we should introduce an S object. It would stand for Script and
>>>> would allow you to do:
>>>>>
>>>>> S.f(“{ it.length }”)
>>>>>
>>>>> Where does this come in handy? Language variants.
>>>>>
>>>>> Imagine using gremlin_python that will compile to Gremlin-Groovy for
>>>> execution at GremlinServer.
>>>>>
>>>>> g.V().out(“knows”)[0:2].name.map(f(“{ it.length }”))
>>>>>
>>>>> Next, imagine you are in Gremlin-Java and want to submit a traversal to
>>>> GremlinServer, but it has a lambda. No worries, just use the
>>>> GroovyTranslator and you have:
>>>>>
>>>>> g.V().out(“knows”).limit(2).values(“name”).map(f(“{ it.length
>>> }”))
>>>>>
>>>>> We could also have:
>>>>>
>>>>> S.s = supplier
>>>>> S.c = consumer
>>>>> S.f = function
>>>>> S.o = operator
>>>>>
>>>>> This gets to the general problem of being able to translate lambdas
>>>> between different languages as well as being able to send lambdas over
>>> the
>>>> wire.
>>>>>
>>>>> Thoughts?,
>>>>> Marko.
>>>>>
>>>>> http://markorodriguez.com <http://markorodriguez.com/>
>>>>> <http://markorodriguez.com/ <http://markorodriguez.com/>>
