internal static void MatchSquareBracketStack(InlineStack opener, Subject subj, Reference details, InlineParserParameters parameters)
{
if (details != null)
{
var inl = opener.StartingInline;
var isImage = 0 != (opener.Flags & InlineStack.InlineStackFlags.ImageLink);
inl.Tag = isImage ? InlineTag.Image : InlineTag.Link;
inl.FirstChild = inl.NextSibling;
inl.NextSibling = null;
inl.SourceLastPosition = subj.Position;
inl.TargetUrl = details.Url;
inl.LiteralContent = details.Title;
if (!isImage)
{
// since there cannot be nested links, remove any other link openers before this
var temp = opener.Previous;
while (temp != null && temp.Priority <= InlineStack.InlineStackPriority.Links)
{
if (temp.Delimeter == '[' && temp.Flags == opener.Flags)
{
// mark the previous entries as "inactive"
if (temp.DelimeterCount == -1)
break;
temp.DelimeterCount = -1;
}
temp = temp.Previous;
}
}
InlineStack.RemoveStackEntry(opener, subj, null, parameters);
subj.LastInline = inl;
}
else
{
// this looked like a link, but was not.
// remove the opener stack entry but leave the inbetween intact
InlineStack.RemoveStackEntry(opener, subj, opener, parameters);
var inl = new Inline("]", subj.Position - 1, subj.Position);
subj.LastInline.LastSibling.NextSibling = inl;
subj.LastInline = inl;
}
}
private static Inline HandleOpenerCloser(Subject subj, InlineTag singleCharTag, InlineTag doubleCharTag, InlineParserParameters parameters)
{
bool canOpen, canClose;
var c = subj.Buffer[subj.Position];
var numdelims = ScanEmphasisDelimeters(subj, c, out canOpen, out canClose);
if (canClose)
{
// walk the stack and find a matching opener, if there is one
var istack = InlineStack.FindMatchingOpener(subj.LastPendingInline, InlineStack.InlineStackPriority.Emphasis, c, out canClose);
if (istack != null)
{
var useDelims = MatchInlineStack(istack, subj, numdelims, null, singleCharTag, doubleCharTag, parameters);
// if the closer was not fully used, move back a char or two and try again.
if (useDelims < numdelims)
{
subj.Position = subj.Position - numdelims + useDelims;
// use recursion only if it will not be very deep.
if (numdelims < 10)
return HandleOpenerCloser(subj, singleCharTag, doubleCharTag, parameters);
}
return null;
}
}
var inlText = new Inline(subj.Buffer, subj.Position - numdelims, numdelims, subj.Position - numdelims, subj.Position, c);
if (canOpen || canClose)
{
var istack = new InlineStack();
istack.DelimeterCount = numdelims;
istack.Delimeter = c;
istack.StartingInline = inlText;
istack.Priority = InlineStack.InlineStackPriority.Emphasis;
istack.Flags = (canOpen ? InlineStack.InlineStackFlags.Opener : 0)
| (canClose ? InlineStack.InlineStackFlags.Closer : 0);
InlineStack.AppendStackEntry(istack, subj);
}
return inlText;
}
/// <summary>
/// Initializes the array of delegates for inline emphasis parsing.
/// </summary>
/// <returns></returns>
internal static Func<Subject, Inline>[] InitializeEmphasisParsers(InlineParserParameters parameters)
{
var p = new Func<Subject, Inline>[96];
p['_'] = p['*'] = s => HandleOpenerCloser(s, InlineTag.Emphasis, InlineTag.Strong, parameters);
return p;
}
internal static int MatchInlineStack(InlineStack opener, Subject subj, int closingDelimeterCount, InlineStack closer, InlineTag singleCharTag, InlineTag doubleCharTag, InlineParserParameters parameters)
{
// calculate the actual number of delimeters used from this closer
int useDelims;
var openerDelims = opener.DelimeterCount;
if (closingDelimeterCount < 3 || openerDelims < 3)
{
useDelims = closingDelimeterCount <= openerDelims ? closingDelimeterCount : openerDelims;
if (useDelims == 2 && doubleCharTag == 0)
useDelims = 1;
if (useDelims == 1 && singleCharTag == 0)
return 0;
}
else if (singleCharTag == 0)
useDelims = 2;
else if (doubleCharTag == 0)
useDelims = 1;
else
useDelims = closingDelimeterCount % 2 == 0 ? 2 : 1;
Inline inl = opener.StartingInline;
InlineTag tag = useDelims == 1 ? singleCharTag : doubleCharTag;
if (openerDelims == useDelims)
{
// the opener is completely used up - remove the stack entry and reuse the inline element
inl.Tag = tag;
inl.LiteralContent = null;
inl.FirstChild = inl.NextSibling;
inl.NextSibling = null;
InlineStack.RemoveStackEntry(opener, subj, closer?.Previous, parameters);
}
else
{
// the opener will only partially be used - stack entry remains (truncated) and a new inline is added.
opener.DelimeterCount -= useDelims;
inl.LiteralContent = inl.LiteralContent.Substring(0, opener.DelimeterCount);
inl.SourceLastPosition -= useDelims;
inl.NextSibling = new Inline(tag, inl.NextSibling);
inl = inl.NextSibling;
inl.SourcePosition = opener.StartingInline.SourcePosition + opener.DelimeterCount;
}
// there are two callers for this method, distinguished by the `closer` argument.
// if closer == null it means the method is called during the initial subject parsing and the closer
// characters are at the current position in the subject. The main benefit is that there is nothing
// parsed that is located after the matched inline element.
// if closer != null it means the method is called when the second pass for previously unmatched
// stack elements is done. The drawback is that there can be other elements after the closer.
if (closer != null)
{
var clInl = closer.StartingInline;
if ((closer.DelimeterCount -= useDelims) > 0)
{
// a new inline element must be created because the old one has to be the one that
// finalizes the children of the emphasis
var newCloserInline = new Inline(clInl.LiteralContent.Substring(useDelims));
newCloserInline.SourcePosition = inl.SourceLastPosition = clInl.SourcePosition + useDelims;
newCloserInline.SourceLength = closer.DelimeterCount;
newCloserInline.NextSibling = clInl.NextSibling;
clInl.LiteralContent = null;
clInl.NextSibling = null;
inl.NextSibling = closer.StartingInline = newCloserInline;
}
else
{
inl.SourceLastPosition = clInl.SourceLastPosition;
clInl.LiteralContent = null;
inl.NextSibling = clInl.NextSibling;
clInl.NextSibling = null;
}
}
else if (subj != null)
{
inl.SourceLastPosition = subj.Position - closingDelimeterCount + useDelims;
subj.LastInline = inl;
}
return useDelims;
}
public static Inline parse_inlines(Subject subj, Dictionary<string, Reference> refmap, InlineParserParameters parameters)
{
var len = subj.Length;
if (len == 0)
return null;
var first = ParseInline(subj, parameters);
subj.LastInline = first.LastSibling;
Inline cur;
while (subj.Position < len)
{
cur = ParseInline(subj, parameters);
if (cur != null)
{
subj.LastInline.NextSibling = cur;
subj.LastInline = cur.LastSibling;
}
}
InlineStack.PostProcessInlineStack(subj, subj.FirstPendingInline, subj.LastPendingInline, InlineStack.InlineStackPriority.Maximum, parameters);
return first;
}
/// <summary>
/// Parse an inline element from the subject. The subject position is updated to after the element.
/// </summary>
public static Inline ParseInline(Subject subj, InlineParserParameters parameters)
{
var parsers = parameters.Parsers;
var specialCharacters = parameters.SpecialCharacters;
var c = subj.Buffer[subj.Position];
var parser = c < parsers.Length ? parsers[c] : null;
if (parser != null)
return parser(subj);
var startpos = subj.Position;
// we read until we hit a special character
// +1 is so that any special character at the current position is ignored.
var endpos = subj.Buffer.IndexOfAny(specialCharacters, startpos + 1, subj.Length - startpos - 1);
if (endpos == -1)
endpos = subj.Length;
subj.Position = endpos;
// if we're at a newline, strip trailing spaces.
if (endpos < subj.Length && subj.Buffer[endpos] == '\n')
while (endpos > startpos && subj.Buffer[endpos - 1] == ' ')
endpos--;
return new Inline(subj.Buffer, startpos, endpos - startpos, startpos, endpos, c);
}
public static void PostProcessInlineStack(Subject subj, InlineStack first, InlineStack last, InlineStackPriority ignorePriority, InlineParserParameters parameters)
{
var singleCharTags = parameters.SingleCharTags;
var doubleCharTags = parameters.DoubleCharTags;
while (ignorePriority > 0)
{
var istack = first;
while (istack != null)
{
if (istack.Priority >= ignorePriority)
{
RemoveStackEntry(istack, subj, istack, parameters);
}
else if (0 != (istack.Flags & InlineStackFlags.Closer))
{
bool canClose;
var iopener = FindMatchingOpener(istack.Previous, istack.Priority, istack.Delimeter, out canClose);
if (iopener != null)
{
bool retry = false;
var singleCharTag = iopener.Delimeter < singleCharTags.Length ? singleCharTags[iopener.Delimeter] : (InlineTag)0;
var doubleCharTag = iopener.Delimeter < doubleCharTags.Length ? doubleCharTags[iopener.Delimeter] : (InlineTag)0;
if (singleCharTag != 0 || doubleCharTag != 0)
{
var useDelims = InlineMethods.MatchInlineStack(iopener, subj, istack.DelimeterCount, istack, singleCharTag, doubleCharTag, parameters);
if (istack.DelimeterCount > 0)
retry = true;
}
if (retry)
{
// remove everything between opened and closer (not inclusive).
if (istack.Previous != null && iopener.Next != istack.Previous)
RemoveStackEntry(iopener.Next, subj, istack.Previous, parameters);
continue;
}
else
{
// remove opener, everything in between, and the closer
RemoveStackEntry(iopener, subj, istack, parameters);
}
}
else if (!canClose)
{
// this case means that a matching opener does not exist
// remove the Closer flag so that a future Opener can be matched against it.
istack.Flags &= ~InlineStackFlags.Closer;
}
}
if (istack == last)
break;
istack = istack.Next;
}
ignorePriority--;
}
}
/// <summary>
/// Removes a subset of the stack.
/// </summary>
/// <param name="first">The first entry to be removed.</param>
/// <param name="subj">The subject associated with this stack. Can be <c>null</c> if the pointers in the subject should not be updated.</param>
/// <param name="last">The last entry to be removed. Can be <c>null</c> if everything starting from <paramref name="first"/> has to be removed.</param>
/// <param name="parameters">Inline parser parameters.</param>
public static void RemoveStackEntry(InlineStack first, Subject subj, InlineStack last, InlineParserParameters parameters)
{
var curPriority = first.Priority;
if (last == null)
{
if (first.Previous != null)
first.Previous.Next = null;
else if (subj != null)
subj.FirstPendingInline = null;
if (subj != null)
{
last = subj.LastPendingInline;
subj.LastPendingInline = first.Previous;
}
first = first.Next;
}
else
{
if (first.Previous != null)
first.Previous.Next = last.Next;
else if (subj != null)
subj.FirstPendingInline = last.Next;
if (last.Next != null)
last.Next.Previous = first.Previous;
else if (subj != null)
subj.LastPendingInline = first.Previous;
if (first == last)
return;
first = first.Next;
last = last.Previous;
}
if (last == null || first == null)
return;
first.Previous = null;
last.Next = null;
// handle case like [*b*] (the whole [..] is being removed but the inner *..* must still be matched).
// this is not done automatically because the initial * is recognized as a potential closer (assuming
// potential scenario '*[*' ).
if (curPriority > 0)
PostProcessInlineStack(null, first, last, curPriority, parameters);
}
