let downView = try? DownView(frame: self.view.bounds, markdownString: "**Oh Hai**") {
    // Optional callback for loading finished
}
// Now add to view or constrain w/ Autolayout
// Or you could optionally update the contents at some point:
try? downView?.update(markdownString:  "## [Google](https://google.com)") {
    // Optional callback for loading finished
}

let down = Down(markdownString: "## [Down](https://github.com/johnxnguyen/Down)")

// Convert to HTML
let html = try? down.toHTML()
// "<h2><a href=\"https://github.com/johnxnguyen/Down\">Down</a></h2>\n"

// Convert to XML
let xml = try? down.toXML()
// "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<!DOCTYPE document SYSTEM \"CommonMark.dtd\">\n<document xmlns=\"http://commonmark.org/xml/1.0\">\n  <heading level=\"2\">\n    <link destination=\"https://github.com/johnxnguyen/Down\" title=\"\">\n      <text>Down</text>\n    </link>\n  </heading>\n</document>\n"

// Convert to groff man
let man = try? down.toGroff()
// ".SS\nDown (https://github.com/johnxnguyen/Down)\n"

// Convert to LaTeX
let latex = try? down.toLaTeX()
// "\\subsection{\\href{https://github.com/johnxnguyen/Down}{Down}}\n"

// Convert to CommonMark Markdown
let commonMark = try? down.toCommonMark()
// "## [Down](https://github.com/johnxnguyen/Down)\n"

// Convert to an attributed string
let attributedString = try? down.toAttributedString()
// NSAttributedString representation of the rendered HTML;
// by default, uses a stylesheet that matches NSAttributedString's default font,
// but you can override this by passing in your own, using the 'stylesheet:' parameter.

// Convert to abstract syntax tree
let ast = try? down.toAST()
// Returns pointer to AST that you can manipulate

public struct MarkdownToHTML: DownHTMLRenderable {
    /**
     A string containing CommonMark Markdown
    */
    public var markdownString: String

    /**
     Initializes the container with a CommonMark Markdown string which can then be rendered as HTML using `toHTML()`

     - parameter markdownString: A string containing CommonMark Markdown

     - returns: An instance of Self
     */
    @warn_unused_result
    public init(markdownString: String) {
        self.markdownString = markdownString
    }
}

/**
 Default options
*/
public static let `default` = DownOptions(rawValue: 0)

// MARK: - Rendering Options

/**
 Include a `data-sourcepos` attribute on all block elements
*/
public static let sourcePos = DownOptions(rawValue: 1 << 1)

/**
 Render `softbreak` elements as hard line breaks.
*/
public static let hardBreaks = DownOptions(rawValue: 1 << 2)

/**
 Suppress raw HTML and unsafe links (`javascript:`, `vbscript:`,
 `file:`, and `data:`, except for `image/png`, `image/gif`,
 `image/jpeg`, or `image/webp` mime types).  Raw HTML is replaced
 by a placeholder HTML comment. Unsafe links are replaced by
 empty strings. Note that this option is provided for backwards
 compatibility, but safe mode is now the default.
*/
public static let safe = DownOptions(rawValue: 1 << 3)

/**
 Allow raw HTML and unsafe links. Note that safe mode is now
 the default, and the unsafe option must be used if rendering
 of raw HTML and unsafe links is desired.
*/
public static let unsafe = DownOptions(rawValue: 1 << 17)

// MARK: - Parsing Options

/**
 Normalize tree by consolidating adjacent text nodes.
*/
public static let normalize = DownOptions(rawValue: 1 << 4)

/**
 Validate UTF-8 in the input before parsing, replacing illegal
 sequences with the replacement character U FFFD.
*/
public static let validateUTF8 = DownOptions(rawValue: 1 << 5)

/**
 Convert straight quotes to curly, --- to em dashes, -- to en dashes.
*/
public static let smart = DownOptions(rawValue: 1 << 6)

/**
 Combine smart typography with HTML rendering.
*/
public static let smartUnsaFe = DownOptions(rawValue: (1 << 17)   (1 << 6))