I need to get a range from string. ; - is a delimeter.
So, for example i have string "10;15;1" and i need to get range from 10 to 15(ignoring the last number).
Expecting result:
"10;15;1" -> 10..15
So i tryed to write this code. How can i improove it? it looks bad and innefective
val arr = "10;15;1".split(";").dropLast(1).map { it.toBigDecimal() } val someRange = arr[0] .. arr[1] If you don't care about validation, you could do this:
fun toRange(str: String): IntRange = str .split(";") .let { (a, b) -> a.toInt()..b.toInt() } fun main() { println(toRange("10;15;1")) } Output:
10..15 If you want to be more paranoid:
fun toRange(str: String): IntRange { val split = str.split(";") require(split.size >= 2) { "str must contain two integers separated by ;" } val (a, b) = split return try { a.toInt()..b.toInt() } catch (e: NumberFormatException) { throw IllegalArgumentException("str values '$a' and/or '$b' are not integers", e) } } fun main() { try { println(toRange("oops")) } catch (e: IllegalArgumentException) { println(e.message) } try { println(toRange("foo;bar;baz")) } catch (e: IllegalArgumentException) { println(e.message) } println(toRange("10;15;1")) } Output:
str must contain two integers separated by ; str values 'foo' and/or 'bar' are not integers 10..15 The function is very specific so it must not exist in the standard library. I have nothing against the implementation although I can suggest alternatives using a Regex and returning a null value if the string is not well formed. But it uses regex.
fun rangeFrom(str: String) : ClosedRange<BigDecimal>? { val regex = """^(\d+);(\d+);\d+$""".toRegex() val result = regex.find(str) return result?.destructured?.let { (fst, snd) -> fst.toBigDecimal() .. snd.toBigDecimal() } } Or you can just update your function checking that the length of the list produced by split is >= 2 and directly using arr[0].toBigDecimal() .. arr[1].toBigDecimal but it is not very different.
Intmight be simpler thanBigDecimal. This looks too specific to be worth splitting out to a separate function, unless you can make it more general somehow.map(String::toBigDecimal)so the code is more self-documenting without losing its conciseness.