static IList <EbnfMessage> _TryParseExpressions(ParseNode parent, int firstChildIndex, out EbnfExpression result)
{
var msgs = new List <EbnfMessage>();
result = null;
var or = new List <IList <EbnfExpression> >();
var seq = new List <EbnfExpression>();
for (int ic = parent.Children.Count, i = firstChildIndex; i < ic; ++i)
{
EbnfExpression expr;
var pn = parent.Children[i];
switch (pn.SymbolId)
{
case EbnfParser.expression:
msgs.AddRange(_TryParseExpression(parent.Children[i], out expr));
seq.Add(expr);
break;
case EbnfParser.or:
or.Add(seq);
seq = new List <EbnfExpression>();
break;
default:
break;
}
}
or.Add(seq);
result = null;
switch (or.Count)
{
case 0:
result = null;
break;
case 1:
result = _SeqToExpression(or[0]);
break;
default:
var state = 0;
var oe = new EbnfOrExpression();
for (int ic = or.Count, i = 0; i < ic; ++i)
{
switch (state)
{
case 0:
oe.Left = _SeqToExpression(or[i]);
state = 1;
break;
case 1:
oe.Right = _SeqToExpression(or[i]);
state = 2;
break;
case 2:
oe = new EbnfOrExpression(oe, null);
oe.Right = _SeqToExpression(or[i]);
break;
}
}
//if (0 == state || 2 == state)
// result = oe.Left;
//else
result = oe;
break;
}
return(msgs);
}
static EbnfExpression _ParseExpression(EbnfDocument doc, ParseContext pc)
{
EbnfExpression current = null;
EbnfExpression 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();
current = new EbnfOrExpression(current, _ParseExpression(doc, pc));
current.SetLocationInfo(line, column, position);
break;
case '(':
pc.Advance();
e = _ParseExpression(doc, pc);
current.SetLocationInfo(line, column, position);
pc.Expecting(')');
pc.Advance();
e.SetLocationInfo(line, column, position);
if (null == current)
{
current = e;
}
else
{
current = new EbnfConcatExpression(current, e);
}
break;
case '[':
pc.Advance();
e = new EbnfOptionalExpression(_ParseExpression(doc, pc));
e.SetLocationInfo(line, column, position);
pc.TrySkipCCommentsAndWhiteSpace();
pc.Expecting(']');
pc.Advance();
if (null == current)
{
current = e;
}
else
{
current = new EbnfConcatExpression(current, e);
}
break;
case '{':
pc.Advance();
e = new EbnfRepeatExpression(_ParseExpression(doc, pc));
e.SetLocationInfo(line, column, position);
pc.TrySkipCCommentsAndWhiteSpace();
pc.Expecting('}');
pc.Advance();
if ('+' == pc.Current)
{
pc.Advance();
((EbnfRepeatExpression)e).IsOptional = false;
}
if (null == current)
{
current = e;
}
else
{
current = new EbnfConcatExpression(current, e);
}
break;
case '\"':
e = new EbnfLiteralExpression(pc.ParseJsonString());
if (null == current)
{
current = e;
}
else
{
current = new EbnfConcatExpression(current, e);
}
e.SetLocationInfo(line, column, position);
break;
case '\'':
pc.Advance();
pc.ClearCapture();
pc.TryReadUntil('\'', '\\', false);
pc.Expecting('\'');
pc.Advance();
e = new EbnfRegexExpression(pc.Capture);
if (null == current)
{
current = e;
}
else
{
current = new EbnfConcatExpression(current, e);
}
e.SetLocationInfo(line, column, position);
break;
case ';':
case ']':
case ')':
case '}':
return(current);
default:
e = new EbnfRefExpression(_ParseIdentifier(pc));
if (null == current)
{
current = e;
}
else
{
current = new EbnfConcatExpression(current, e);
}
e.SetLocationInfo(line, column, position);
break;
}
}
pc.TrySkipCCommentsAndWhiteSpace();
return(current);
}
public override IList <IList <string> > ToDisjunctions(EbnfDocument parent, Cfg cfg)
{
string sid = null;
var sr = Expression as EbnfRefExpression;
if (null != parent && null != sr)
{
sid = string.Concat(sr.Symbol, "list");
}
if (string.IsNullOrEmpty(sid))
{
var cc = Expression as EbnfConcatExpression;
if (null != cc)
{
sr = cc.Right as EbnfRefExpression;
if (null != sr)
{
sid = string.Concat(sr.Symbol, "listtail");
}
}
}
if (string.IsNullOrEmpty(sid))
{
sid = "implicitlist";
}
var _listId = cfg.GetUniqueId(sid);
var attrs = new AttributeSet();
attrs.Add("collapsed", true);
cfg.AttributeSets.Add(_listId, attrs);
var expr =
new EbnfOrExpression(
new EbnfConcatExpression(
new EbnfRefExpression(_listId), Expression), Expression);
//if (IsOptional)
// expr = new EbnfOrExpression(expr, null);
foreach (var nt in expr.ToDisjunctions(parent, cfg))
{
CfgRule r = new CfgRule();
r.Left = _listId;
foreach (var s in nt)
{
if (1 < r.Right.Count && null == s)
{
continue;
}
r.Right.Add(s);
}
if (!cfg.Rules.Contains(r))
{
cfg.Rules.Add(r);
}
}
if (!IsOptional)
{
return(new List <IList <string> >(new IList <string>[] { new List <string>(new string[] { _listId }) }));
}
else
{
var result = new List <IList <string> >();
result.Add(new List <string>(new string[] { _listId }));
result.Add(new List <string>());
return(result);
}
}