hexToLong

fun String.hexToLong(format: HexFormat = HexFormat.Default): Long(source)

import kotlin.text.HexFormat

fun main() {
    val hexString = "1A3F"
    val number: Long = hexString.hexToLong()          // uses HexFormat.Default
    println("Hex $hexString as Long: $number")        // prints: Hex 1A3F as Long: 6719

    // With a custom format (e.g., uppercase and 4 digits)
    val customNumber = hexString.hexToLong(
        HexFormat { it.letterCase = HexFormat.LetterCase.UPPER; it.minimumWidth = 4 }
    )
    println("Custom format: $customNumber")            // prints: Custom format: 6719
}