I want to support strike through with like this ~text~ instead of ~~text~~

[ajayalivecor]

For this i have created a custom class by conforming to protocol MarkDownCommonElement, the match method is not being called at all.

class MarkdownCustomStrikethrough: MarkdownCommonElement {
fileprivate static let regex = "(?<=\S)(~~)(?=\S)(.+?)(?<=\S)(\1)"

open var font: MarkdownFont?
open var color: MarkdownColor?
public var attributes: [NSAttributedString.Key: AnyObject] = [.strikethroughStyle: NSNumber(value: NSUnderlineStyle.single.rawValue)]

open var regex: String {
    return MarkdownCustomStrikethrough.regex
}

public init(font: MarkdownFont? = nil, color: MarkdownColor? = nil) {
    self.font = font
    self.color = color
    print("MarkdownCustomStrikethrough init called")
}

func regularExpression() throws -> NSRegularExpression {
    print("MarkdownCustomStrikethrough regularExpression called")
    return try NSRegularExpression(pattern: regex, options: [])
}

func addAttributes(_ attributedString: NSMutableAttributedString, range: NSRange) {
    attributedString.addAttributes(attributes, range: range)
    
    if let font = font {
        attributedString.addAttribute(.font, value: font, range: range)
    }
    
    if let color = color {
        attributedString.addAttribute(.foregroundColor, value: color, range: range)
    }
}

func match(_ match: NSTextCheckingResult, attributedString: NSMutableAttributedString) {
  // deleting trailing markdown
  attributedString.deleteCharacters(in: match.range(at: 4))
  // formatting string (may alter the length)
  addAttributes(attributedString, range: match.range(at: 3))
  // deleting leading markdown
  attributedString.deleteCharacters(in: match.range(at: 2))
}

}