RdpPattern ReplaceAfterHeadWithEmpty(RdpPattern p)
{
if (p is RdpAbstractSingleContent)
{
return(new RdpChoice(RdpEmpty.Instance, p));
}
RdpAbstractBinary ab = p as RdpAbstractBinary;
if (ab == null)
{
return(p);
}
if (ab is RdpGroup)
{
return(new RdpGroup(ReplaceAfterHeadWithEmpty(ab.LValue), ReplaceAfterHeadWithEmpty(ab.RValue)));
}
else if (ab is RdpChoice)
{
return(new RdpChoice(ReplaceAfterHeadWithEmpty(ab.LValue), ReplaceAfterHeadWithEmpty(ab.RValue)));
}
else if (ab is RdpInterleave)
{
return(new RdpInterleave(ReplaceAfterHeadWithEmpty(ab.LValue), ReplaceAfterHeadWithEmpty(ab.RValue)));
}
else if (ab is RdpAfter)
{
return(new RdpAfter(RdpEmpty.Instance, ab.RValue));
}
throw new SystemException("INTERNAL ERROR: unexpected pattern: " + p.GetType());
}
// Error recovery feature can be enabled by using
// InvalidNodeFound event of type RelaxngValidationEventHandler.
//
// Other than startTagOpenDeriv, it is (again) based on
// James Clark's derivative algorithm.
// http://www.thaiopensource.com/relaxng/derivative.html
// For invalid start tag, we just recover from it by using
// xs:any-like pattern for unexpected node occurence.
RdpPattern MakeGroupHeadOptional(RdpPattern p)
{
if (p is RdpAbstractSingleContent)
{
return(new RdpChoice(RdpEmpty.Instance, p));
}
RdpAbstractBinary ab = p as RdpAbstractBinary;
if (ab == null)
{
return(p);
}
if (ab is RdpGroup)
{
return(new RdpGroup(new RdpChoice(RdpEmpty.Instance, ab.LValue), ab.RValue));
}
else if (ab is RdpChoice)
{
return(new RdpChoice(MakeGroupHeadOptional(ab.LValue), MakeGroupHeadOptional(ab.RValue)));
}
else if (ab is RdpInterleave)
{
return(new RdpInterleave(MakeGroupHeadOptional(ab.LValue), MakeGroupHeadOptional(ab.RValue)));
}
else if (ab is RdpAfter) // FIXME: is it correct?
{
return(new RdpAfter(MakeGroupHeadOptional(ab.LValue), MakeGroupHeadOptional(ab.RValue)));
}
throw new SystemException("INTERNAL ERROR: unexpected pattern: " + p.GetType());
}
RdpPattern ReplaceAttributesWithEmpty(RdpPattern p)
{
if (p is RdpAttribute)
{
return(RdpEmpty.Instance);
}
RdpAbstractSingleContent asc = p as RdpAbstractSingleContent;
if (asc is RdpList)
{
return(new RdpList(ReplaceAttributesWithEmpty(asc.Child)));
}
if (asc is RdpOneOrMore)
{
return(new RdpOneOrMore(ReplaceAttributesWithEmpty(asc.Child)));
}
else if (asc is RdpElement)
{
return(asc); // should not be expected to contain any attribute as RdpElement.
}
RdpAbstractBinary ab = p as RdpAbstractBinary;
if (ab == null)
{
return(p);
}
if (ab is RdpGroup)
{
return(new RdpGroup(ReplaceAttributesWithEmpty(ab.LValue), ReplaceAttributesWithEmpty(ab.RValue)));
}
else if (ab is RdpChoice)
{
return(new RdpChoice(ReplaceAttributesWithEmpty(ab.LValue), ReplaceAttributesWithEmpty(ab.RValue)));
}
else if (ab is RdpInterleave)
{
return(new RdpInterleave(ReplaceAttributesWithEmpty(ab.LValue), ReplaceAttributesWithEmpty(ab.RValue)));
}
else if (ab is RdpAfter) // FIXME: is it correct?
{
return(new RdpAfter(ReplaceAttributesWithEmpty(ab.LValue), ReplaceAttributesWithEmpty(ab.RValue)));
}
throw new SystemException("INTERNAL ERROR: unexpected pattern: " + p.GetType());
}