static void _VisitFetchTerminals(XbnfExpression expr, HashSet <XbnfExpression> terms)
{
var l = expr as XbnfLiteralExpression;
if (null != l)
{
terms.Add(l);
return;
}
var r = expr as XbnfRegexExpression;
if (null != r)
{
terms.Add(r);
return;
}
var u = expr as XbnfUnaryExpression;
if (null != u)
{
_VisitFetchTerminals(u.Expression, terms);
return;
}
var b = expr as XbnfBinaryExpression;
if (null != b)
{
_VisitFetchTerminals(b.Left, terms);
_VisitFetchTerminals(b.Right, terms);
return;
}
}
internal static XbnfProduction Parse(ParseContext pc)
{
var result = new XbnfProduction();
pc.TrySkipCCommentsAndWhiteSpace();
// read identifier
result.Name = ParseIdentifier(pc);
// read attributes
if ('<' == pc.Current)
{
pc.Advance();
while (-1 != pc.Current && '>' != pc.Current)
{
result.Attributes.Add(XbnfAttribute.Parse(pc));
pc.TrySkipCCommentsAndWhiteSpace();
pc.Expecting('>', ',');
if (',' == pc.Current)
{
pc.Advance();
}
}
pc.Expecting('>');
pc.Advance();
}
pc.TrySkipCCommentsAndWhiteSpace();
pc.Expecting(';', '=');
if ('=' == pc.Current)
{
pc.Advance();
result.Expression = XbnfExpression.Parse(pc);
}
pc.Expecting(';');
pc.Advance();
return(result);
}
static XbnfProduction _GetProductionForExpression(XbnfDocument d, XbnfExpression e)
{
for (int ic = d.Productions.Count, i = 0; i < ic; ++i)
{
var prod = d.Productions[i];
if (e == prod.Expression)
{
return(prod);
}
}
return(null);
}
static string _ToRegex(XbnfDocument d, XbnfExpression e)
{
var le = e as XbnfLiteralExpression;
if (null != le)
{
return(_EscapeLiteral(XbnfNode.Escape(le.Value)));
}
var rxe = e as XbnfRegexExpression;
if (null != rxe)
{
return(string.Concat("(", rxe.Value, ")"));
}
var rfe = e as XbnfRefExpression;
if (null != rfe)
{
_ToRegex(d, d.Productions[rfe.Symbol].Expression);
}
var re = e as XbnfRepeatExpression;
if (null != re)
{
if (re.IsOptional)
{
return(string.Concat("(", _ToRegex(d, re.Expression), ")*"));
}
else
{
return(string.Concat("(", _ToRegex(d, re.Expression), ")+"));
}
}
var oe = e as XbnfOrExpression;
if (null != oe)
{
return(string.Concat("(", _ToRegex(d, oe.Left), "|", _ToRegex(d, oe.Right), ")"));
}
var oc = e as XbnfConcatExpression;
if (null != oc)
{
return(string.Concat(_ToRegex(d, oe.Left), _ToRegex(d, oe.Right)));
}
var ope = e as XbnfOptionalExpression;
if (null != ope)
{
return(string.Concat("(", _ToRegex(d, ope.Expression), ")?"));
}
return("");
}
public XbnfConcatExpression(XbnfExpression left, params XbnfExpression[] right)
{
Left = left;
for (int i = 0; i < right.Length; i++)
{
var r = right[i];
if (null == Right)
{
Right = r;
}
else
{
var c = new XbnfConcatExpression();
c.Left = Left;
c.Right = Right;
Right = null;
Left = c;
}
}
}
public XbnfProduction(string name, XbnfExpression expression = null)
{
Name = name;
Expression = expression;
}
internal static XbnfExpression Parse(ParseContext pc)
{
XbnfExpression current = null;
XbnfExpression e;
long position;
int line;
int column;
pc.TrySkipCCommentsAndWhiteSpace();
position = pc.Position; line = pc.Line; column = pc.Column;
while (-1 != pc.Current && ']' != pc.Current && ')' != pc.Current && '}' != pc.Current && ';' != pc.Current)
{
pc.TrySkipCCommentsAndWhiteSpace();
position = pc.Position; line = pc.Line; column = pc.Column;
switch (pc.Current)
{
case '|':
pc.Advance();
position = pc.Position; line = pc.Line; column = pc.Column;
current = new XbnfOrExpression(current, Parse(pc));
current.SetLocation(line, column, position);
break;
case '(':
pc.Advance();
position = pc.Position; line = pc.Line; column = pc.Column;
e = Parse(pc);
current.SetLocation(line, column, position);
pc.Expecting(')');
pc.Advance();
e.SetLocation(line, column, position);
if (null == current)
{
current = e;
}
else
{
current = new XbnfConcatExpression(current, e);
}
break;
case '[':
pc.Advance();
e = new XbnfOptionalExpression(Parse(pc));
e.SetLocation(line, column, position);
pc.TrySkipCCommentsAndWhiteSpace();
pc.Expecting(']');
pc.Advance();
if (null == current)
{
current = e;
}
else
{
current = new XbnfConcatExpression(current, e);
}
break;
case '{':
pc.Advance();
e = new XbnfRepeatExpression(Parse(pc));
e.SetLocation(line, column, position);
pc.TrySkipCCommentsAndWhiteSpace();
pc.Expecting('}');
pc.Advance();
if ('+' == pc.Current)
{
pc.Advance();
((XbnfRepeatExpression)e).IsOptional = false;
}
if (null == current)
{
current = e;
}
else
{
current = new XbnfConcatExpression(current, e);
}
break;
case '\"':
e = new XbnfLiteralExpression(pc.ParseJsonString());
if (null == current)
{
current = e;
}
else
{
current = new XbnfConcatExpression(current, e);
}
e.SetLocation(line, column, position);
break;
case '\'':
pc.Advance();
pc.ClearCapture();
pc.TryReadUntil('\'', '\\', false);
pc.Expecting('\'');
pc.Advance();
e = new XbnfRegexExpression(pc.GetCapture());
if (null == current)
{
current = e;
}
else
{
current = new XbnfConcatExpression(current, e);
}
e.SetLocation(line, column, position);
break;
case ';':
case ']':
case ')':
case '}':
return(current);
default:
e = new XbnfRefExpression(ParseIdentifier(pc));
if (null == current)
{
current = e;
}
else
{
current = new XbnfConcatExpression(current, e);
}
e.SetLocation(line, column, position);
break;
}
}
pc.TrySkipCCommentsAndWhiteSpace();
return(current);
}
static IList <IList <string> > _GetDysjunctions(
XbnfDocument d,
ICollection <string> syms,
IDictionary <XbnfExpression, string> tmap,
IDictionary <string, XbnfAttributeList> attrs,
IList <KeyValuePair <string, IList <string> > > rules,
XbnfProduction p,
XbnfExpression e
)
{
var le = e as XbnfLiteralExpression;
if (null != le)
{
var res = new List <IList <string> >();
var l = new List <string>();
l.Add(tmap[le]);
res.Add(l);
return(res);
}
var rxe = e as XbnfRegexExpression;
if (null != rxe)
{
var res = new List <IList <string> >();
var l = new List <string>();
l.Add(tmap[rxe]);
res.Add(l);
return(res);
}
var rfe = e as XbnfRefExpression;
if (null != rfe)
{
var res = new List <IList <string> >();
var l = new List <string>();
l.Add(rfe.Symbol);
res.Add(l);
return(res);
}
var ce = e as XbnfConcatExpression;
if (null != ce)
{
return(_GetDysConcat(d, syms, tmap, attrs, rules, p, ce));
}
var oe = e as XbnfOrExpression;
if (null != oe)
{
return(_GetDysOr(d, syms, tmap, attrs, rules, p, oe));
}
var ope = e as XbnfOptionalExpression;
if (null != ope)
{
return(_GetDysOptional(d, syms, tmap, attrs, rules, p, ope));
}
var re = e as XbnfRepeatExpression;
if (null != re)
{
return(_GetDysRepeat(d, syms, tmap, attrs, rules, p, re));
}
throw new NotSupportedException("The specified expression type is not supported.");
}
public XbnfOptionalExpression(XbnfExpression expression)
{
Expression = expression;
}
public XbnfRepeatExpression(XbnfExpression expression, bool isOptional = true)
{
Expression = expression;
IsOptional = isOptional;
}