My String extensions for Kotlin

StringExt.kt

fun String.clipString(
    firstIndex: Int,
    lastIndex: Int,
    includeOneChar: Boolean = true
): String {
    var word = ""

    if (lastIndex >= length) throw IndexOutOfBoundsException()

    if (firstIndex == lastIndex) {
        if (includeOneChar) {
            return this[firstIndex].toString()
        }

        return ""
    }

    for (i in firstIndex..lastIndex) {
        word += this[i]
    }

    return word
}

fun String.remove(s: String): String {
    val index = indexOf(s)
    return if (index != -1) {
        clipString(0, (index - 1).coerceAtLeast(0), index == 1) +
                clipString((index + s.length).coerceAtMost(lastIndex), lastIndex, false)
    } else {
        this
    }
}