matchesAt

@ExperimentalStdlibApi fun matchesAt(
    input: CharSequence, 
    index: Int
): Boolean

Checks if a regular expression matches a part of the specified input char sequence exactly at the specified index.

Unlike matches function, it doesn't require the match to span to the end of input.

fun main(args: Array<String>) {
//sampleStart
val releaseText = "Kotlin 1.5.30 is released!"
val versionRegex = "\\d[.]\\d[.]\\d+".toRegex()
println(versionRegex.matchesAt(releaseText, 0)) // false
println(versionRegex.matchesAt(releaseText, 7)) // true
//sampleEnd
}

Exceptions

IndexOutOfBoundsException - if index is less than zero or greater than the length of the input char sequence.