static void _ParseIncludes(LexContext pc, IList <string> result)
{
pc.TrySkipCCommentsAndWhiteSpace();
while ('@' == pc.Current)
{
pc.Advance();
var s = XbnfNode.ParseIdentifier(pc);
if ("include" == s)
{
pc.TrySkipCCommentsAndWhiteSpace();
var lit = XbnfExpression.Parse(pc) as XbnfLiteralExpression;
if (!result.Contains(lit.Value))
{
result.Add(lit.Value);
}
pc.TryReadCCommentsAndWhitespace();
pc.Advance();
pc.TryReadCCommentsAndWhitespace();
}
else
{
while (-1 != pc.Current && ';' != pc.Current)
{
pc.Advance();
}
if (';' == pc.Current)
{
pc.Advance();
}
pc.TrySkipCCommentsAndWhiteSpace();
}
}
}
internal static XbnfDocument Parse(LexContext pc)
{
var result = new XbnfDocument();
if (!string.IsNullOrEmpty(pc.FileOrUrl))
{
result.SetFilename(pc.FileOrUrl);
}
while (-1 != pc.Current && '}' != pc.Current)
{
pc.TrySkipCCommentsAndWhiteSpace();
while ('@' == pc.Current) // directives
{
pc.Advance();
var l = pc.Line;
var c = pc.Column;
var p = pc.Position;
var str = XbnfNode.ParseIdentifier(pc);
if (0 == string.Compare("include", str, StringComparison.InvariantCulture))
{
result.Includes.Add(_ParseIncludePart(result, pc));
}
else if (0 == string.Compare("options", str, StringComparison.InvariantCulture))
{
if (0 < result.Options.Count)
{
throw new ExpectingException("Duplicate directive \"options\" specified", l, c, p, pc.FileOrUrl);
}
while (-1 != pc.Current && ';' != pc.Current)
{
l = pc.Line;
c = pc.Column;
p = pc.Position;
var opt = XbnfOption.Parse(pc);
opt.SetLocation(l, c, p);
result.Options.Add(opt);
pc.TrySkipCCommentsAndWhiteSpace();
pc.Expecting(';', ',');
if (',' == pc.Current)
{
pc.Advance();
}
}
pc.Expecting(';');
pc.Advance();
if (0 == result.Options.Count)
{
throw new ExpectingException("Expection options but \"options\" directive was empty", l, c, p, pc.FileOrUrl);
}
}
else
{
throw new ExpectingException("Expecting \"include\" or \"options\"", l, c, p, pc.FileOrUrl, "include", "options");
}
pc.TrySkipCCommentsAndWhiteSpace();
}
if (pc.Current == '{')
{
pc.Advance();
var l = pc.Line;
var c = pc.Column;
var p = pc.Position;
var s = ReadCode(pc);
pc.Expecting('}');
pc.Advance();
var code = new XbnfCode(s);
code.SetLocation(l, c, p);
result.Code.Add(code);
}
else if (-1 != pc.Current)
{
if ('@' == pc.Current)
{
throw new ExpectingException("Expecting productions. Includes and options must be specified before any productions", pc.Line, pc.Column, pc.Position, pc.FileOrUrl, "Production");
}
result.Productions.Add(XbnfProduction.Parse(pc));
}
else // end of input
{
return(result);
}
// have to do this so trailing whitespace
// doesn't get read as a production
pc.TryReadCCommentsAndWhitespace();
}
return(result);
}