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kotlinlang

I want to create an extension function to filter a list based on condition x, and if condition x returns an empty list, go for another condition, but I can't figure an idiomatic way to write it; here's what I've got:

more specifically, I want to reuse part of the predicate is my concern

```private inline fun Iterable&lt;TestObject&gt;.emptyFilterIfNotContained(predicate: (TestObject) -&gt; TestObject): List&lt;TestObject&gt;{
  return filterTo(ArrayList(), predicate).ifEmpty{ filterTo(ArrayList(), {it.b.isEmpty()}
}```
but I want b to be variable, as in, be the object that the predicate just compared to

so lets say I called that function with
```test.emptyFilterIfNotContained { it.b.contains('a')} ```
then it should check for b,
but if I sent it.a.contains in the predicate, it should do it.a.isEmpty()

assuming you are comparing string
```private inline fun Iterable&lt;TestObject&gt;.emptyFilterIfNotContained(getValue:(TestObject)-&gt; String, predicate: (String) -&gt; Boolean): List&lt;TestObject&gt;{
    return filterTo(ArrayList()){predicate(getValue(it))}.ifEmpty { filterTo(ArrayList(), { getValue(it).isEmpty() })}
    }```
and use like this
```test.emptyFilterIfNotContained({it.a},{it.contains('a')})```