New Bold Rule

BoldRule.kt

// **This text should be bold.**
val PATTERN_BOLD = Pattern.compile("^\\*\\*([\\s\\S]+?)\\*\\*(?!\\*)")

class BoldRule : Rule(PATTERN_BOLD) {
  override fun parse(matcher: Matcher, parser: Parser): ParseSpec {
    val boldNode = StyleNode(StyleSpan(Typeface.BOLD))
    val innerParseStartIndex = matcher.start(1)
    val innerParseEndIndex = matcher.end(1)

    // Don't actually recursively parse, just return a ParseSpec that informs the Parser
    // what work remains to be done
    return ParseSpec.createNonterminal(boldNode, innerParseStartIndex, innerParseEndIndex)
  }
}