如何实现一个只有digits和一个'.'的可视转换。这就是我尝试实现的方法，但得到偏移错误：

class NumberTransformer : VisualTransformation {

override fun filter(text: AnnotatedString): TransformedText {

    var out = ""
    var dotCount = text.count { it == '.' }
    text.forEach {
        if (it.isDigit())
            out += it.toString().convertToEnglish()
        if (it == '.' && dotCount == 0)  {
            dotCount++
            out += it
        }
    }

    val numberOffsetTranslator = object : OffsetMapping {
        override fun originalToTransformed(offset: Int): Int {
            return offset - dotCount
        }

        override fun transformedToOriginal(offset: Int): Int {
            return offset + dotCount
        }
    }

    return TransformedText(
        text = AnnotatedString(out),
        offsetMapping = numberOffsetTranslator
    )
}
}