arrow-core/arrow.core.computations/NullableEffect/ensure

ensure

open suspend fun ensure(value: Boolean)

Ensure check if the value is true, and if it is it allows the nullable { } binding to continue. In case it is false, then it short-circuits the binding and returns null.

import arrow.core.computations.nullable

//sampleStart
suspend fun main() {
  nullable<Int> {
    ensure(true)
    println("ensure(true) passes")
    ensure(false)
    1
  }
//sampleEnd
  .let(::println)
}
// println: "ensure(true) passes"
// res: null