ifThenElse and return values

[Mike Oxford]

If the pipe finds something, return it.  Otherwise create it.

v1 = g.V.has('p1','abc').has('p2','xyz').ifThenElse{ _().hasNext() } {42} {<removed>}
==>42

Working as expected.

v1 = g.V.has('p1','abc').has('p2','xyz').ifThenElse{ _().hasNext() } {_()} {<removed>}
==>Script72@7cae269e

Not working as expected.

v1 = g.V.has('p1','abc').has('p2','xyz').ifThenElse{ _().hasNext() } {_().next()} {<removed>}
==>Script74@59640688

Not working as expected.

I cannot use .cap ("java.lang.ClassCastException: com.tinkerpop.pipes.branch.IfThenElsePipe cannot be cast to com.tinkerpop.pipes.sideeffect.SideEffectPipe") 

I tried wrapping the whole thing in a closure but that just gave "No such property: cap for class: Script79"

Why does the first one return the value but subsequent ones return what looks to be a reference to the closure itself?  Shouldn't it run the closure and return the result?

How do you get return values out of an ifThenElse pipe?

Thanks!

[Daniel Kuppitz]

Hi Mike,

ifThenElse uses lambdas, hence you shouldn't use the identity pipe. Instead the true and false branches should start with it.

However, it.hasNext() is pointless, as it's always true; otherwise the ifThenElse step wouldn't be evaluated.

Cheers,

Daniel

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