Elvis operator could not contains lambdas or several method calls, only 1 expresion. if var != null could not ensure unwrapping i.e. if var is a class property. These function extensions resolve these problems

OptionalExtension.kt

package com.aracem.android

inline fun <T, K> T?.ifPresent(block: (T) -> K): K? {
    return this?.let { block.invoke(it) }
}

inline fun <K> K?.orElse(block: () -> K): K {
    return this?.let { it } ?: block.invoke()
}

class SampleClass {
    var patatas: List<Patata>?

    fun sampleMethod1(): Tortilla {
        return patatas
            .ifPresent(::makeTortilla)
            .orElse(::makeFrenchTortilla)
    }

    fun makeTortilla(patatas: List<Patata>): Tortilla {
        val cutPatatas = cutPatatas(patatas)
        return makeTortilla(cutPatatas)
    }

    fun makeFrenchTortilla(): Tortilla {
        val shackedEggs = shakeEggs()
        return friedEggs(shackedEggs)
    }
    
    fun shampleMethod2(): Tortilla {
        return patatas
            .ifPresent {
                // No lint warning on it nullability.
                // Using if != null instead would produce a lint warning because
                // patatas could be modified                 
            }. orElse {                
            }
    }
}