void WriteSingleInline(ref Inline inline, char [] escapeChars)
{
switch (inline.Tag)
{
case InlineTag.Emphasis:
case InlineTag.Strong:
var delimeterChar = inline.Emphasis.DelimiterCharacter;
if (delimeterChar == char.MinValue)
{
delimeterChar = '_';
}
var delimeter = new string (
delimeterChar,
inline.Tag == InlineTag.Emphasis ? 1 : 2);
writer.WriteLiteral(delimeter);
WriteInline(inline.FirstChild);
writer.WriteLiteral(delimeter);
break;
case InlineTag.Strikethrough:
writer.WriteLiteral("~~");
WriteInline(inline.FirstChild);
writer.WriteLiteral("~~");
break;
case InlineTag.Placeholder:
writer.WriteLiteral('[');
writer.WriteEscaped(inline.TargetUrl);
writer.WriteLiteral(']');
break;
case InlineTag.Link:
case InlineTag.Image:
// for writing out autolinks, we use this potentially stripped
// URL so we can round-trip email address autolinks.
var targetUrl = inline.TargetUrl;
if (targetUrl.StartsWith("mailto:", StringComparison.Ordinal))
{
targetUrl = targetUrl.Substring(7);
}
// translate links where the target URL and the content are
// the same (and no title is specified) into <autolinks>
if (inline.Tag == InlineTag.Link &&
string.IsNullOrEmpty(inline.LiteralContent) &&
inline.FirstChild != null &&
inline.FirstChild.Tag == InlineTag.String &&
inline.FirstChild.NextSibling == null &&
inline.FirstChild.LiteralContent == targetUrl)
{
writer.WriteLiteral('<');
writer.WriteEscaped(targetUrl);
writer.WriteLiteral('>');
break;
}
// the only difference between a link and an image is ^!
if (inline.Tag == InlineTag.Image)
{
writer.WriteLiteral('!');
}
writer.WriteLiteral('[');
WriteInline(inline.FirstChild, '[', ']');
writer.WriteLiteral(']');
writer.WriteLiteral('(');
writer.WriteEscaped(inline.TargetUrl, '(', ')');
if (!string.IsNullOrEmpty(inline.LiteralContent))
{
writer.WriteLiteral(" \"");
writer.WriteEscaped(inline.LiteralContent, '"', '(', ')');
writer.WriteLiteral('"');
}
writer.WriteLiteral(')');
break;
case InlineTag.Code:
if (string.IsNullOrEmpty(inline.LiteralContent))
{
writer.WriteLiteral("` `");
break;
}
var contentLength = inline.LiteralContent.Length;
var wrapSize = MaxConsecutiveCharCount(inline.LiteralContent, '`') + 1;
writer.WriteLiteral('`', wrapSize);
if (contentLength > 0 && inline.LiteralContent [0] == '`')
{
writer.WriteLiteral(' ');
}
writer.WriteLiteral(inline.LiteralContent);
if (contentLength > 0 && inline.LiteralContent [contentLength - 1] == '`')
{
writer.WriteLiteral(' ');
}
writer.WriteLiteral('`', wrapSize);
break;
case InlineTag.RawHtml:
writer.WriteLiteral(inline.LiteralContent);
break;
case InlineTag.LineBreak:
writer.WriteLiteral('\\');
writer.WriteLineLiteral();
break;
case InlineTag.SoftBreak:
writer.WriteLineLiteral();
var next = inline.NextSibling;
if (next != null &&
next.Tag == InlineTag.String &&
!string.IsNullOrEmpty(next.LiteralContent))
{
switch (next.LiteralContent [0])
{
case '#':
case '-':
case '>':
case '*':
case '=':
writer.WriteLiteral(' ', 4);
break;
}
}
break;
case InlineTag.String:
var content = inline.LiteralContent;
if (string.IsNullOrEmpty(content))
{
break;
}
// CommonMark.NET and the CommonMark JS reference parser appear
// to yield single-character string inlines for characters that
// need escaping. Therefore, we only attempt to escape these
// strings, and not the first character on a string of an arbitray
// length.
switch (content)
{
case "*":
case "_":
case ">":
case "-":
case "#":
case "\\":
case "[":
case "`":
case "<":
writer.WriteEscaped(content [0]);
break;
case "!":
if (inline.NextSibling != null &&
inline.NextSibling.Tag == InlineTag.Link)
{
writer.WriteEscaped('!');
}
else
{
writer.WriteLiteral('!');
}
break;
default:
// match this inline and a next for escaped ordered list
// syntax: ^\d+[\.\)]$ - if the two sibling inlines match,
// we want to escape the list delimeter.
if (inline.NextSibling != null && content.Length < 9 && (
inline.NextSibling.LiteralContent == "." ||
inline.NextSibling.LiteralContent == ")"))
{
var allDigits = true;
for (int i = 0; i < content.Length; i++)
{
if (!char.IsDigit(content [i]))
{
allDigits = false;
break;
}
}
if (allDigits)
{
writer.WriteLiteral(content);
// this will skip over the delimeter inline on the
// next outer loop iteration since we're handling it
// here (escaping it).
inline = inline.NextSibling;
writer.WriteEscaped(inline.LiteralContent [0]);
break;
}
}
writer.WriteEscaped(content, escapeChars);
break;
}
break;
default:
throw new NotImplementedException($"{inline.Tag}");
}
}
