Infix functions in Kotlin

infix_fun_kotlin.kt

/*
 * In Kotlin, a functions marked with infix keyword can also be called using
 * infix notation means calling without using parenthesis and dot.
 */

// Call using dot and parenthesis
var result1 = a.shr(1)

// Call using infix notation
var result2 = a shr 2

// User defined infix member function
infix fun dataType(x: Any): Any {
    var i = when(x) {
        is String -> "String"
        is Int -> "Integer"
        is Double -> "Double"
        else -> "invalid"
        }
    return i
}

/* 
 * This is most commonly seen in the inline Map definition.
 * "to" might look like a special keyword but in this example,
 * this is a to() method leveraging the infix notation and returning a Pair<A, B>.
 */
map(
  1 to "one",
  2 to "two",
  3 to "three"
)