Function return types

GSQL
#1

Hi, I’m experimenting with the ability to write functions and call them.

I have:

CREATE QUERY systemq(VERTEX<system_> sys) FOR GRAPH ty RETURNS (Set<VERTEX<system_>>) 

{ 

  Start={sys};

   RETURN Start;

}

Creating a query that uses this function and prints the results just shows the primary_id however:

CREATE QUERY systemqPrintFromQ(VERTEX<system_> sys) FOR GRAPH ty 

{ 

  PRINT systemq(sys);

}

RESULT:

[

  {

    "systemq(sys)": [

      "WOOL03"

    ]

  }

]

Whereas a query that prints it directly shows the whole object:

CREATE QUERY systemqPrint(VERTEX<system_> sys) FOR GRAPH ty 

{ 

  Start={sys};

  PRINT Start;

}

RESULT:

[

  {

    "Start": [

      {

        "v_id": "WOOL03",

        "v_type": "system_",

        "attributes": {}

      }

    ]

  }

]
```
Is there a way to pass all the parameters back?

Is there a way to do so without adding a mapping step, eg via function composition and lazy evaluation?

Cheers,

Rene
#2

Hi Rene,

To workaround this, you can change your main query to something like this :

create query systemqPrintFromQ(vertex<system_> sys) for graph ty {
SetAccum @@returned;

@@returned = systemq(sys);
printthis = @@returned;

print printthis;

}

This way, you pass the the vertex back into the main query, and activate it, allowing you to print out all of its attributes.

Thanks,
Kevin

#3

Thanks for the response Kevin.

Can you please explain what you mean by “activate”?

IE does putting a variable into an global accumulator “activate” it? What is the difference between activated and non activated variables?

Cheers,

Rene

#4

Sorry if this confused you, I just mean it is stored into memory for immediate use.

Vertices stored in vertex sets will print all attributes - and vertices stored in Set Accumulators will print the vertex id.

Thanks,

Kevin