public virtual void Visit(NullExpression node)
{
this.BeforeVisitCatchAll(node);
}
public override void Visit(NullExpression node)
{
_expressionStack.Push(node, Expression.Constant(null, typeof(object)));
}
private ExpressionNodeBase PromoteToExpression(Token firstToken)
{
ExpressionNodeBase retval;
int intValue;
switch(firstToken.HappyTokenKind)
{
case HappyTokenKind.Identifier:
HappySourceLocation startsAt, endsAt;
if (this.EatNextTokenIf(HappyTokenKind.OperatorOpenParen, out startsAt))
{
List<ExpressionNodeBase> arguments = new List<ExpressionNodeBase>();
bool parseMore = !this.EatNextTokenIf(HappyTokenKind.OperatorCloseParen, out endsAt);
while (parseMore)
{
arguments.Add(this.ParseExpression(ExpressionContext.ArgumentList));
var commaOrCloseParen = this.Expect(HappyTokenKind.Comma, HappyTokenKind.OperatorCloseParen, MiscMessages.CommaOrCloseParen);
endsAt = commaOrCloseParen.Location;
parseMore = commaOrCloseParen.HappyTokenKind != HappyTokenKind.OperatorCloseParen;
}
retval = new FunctionCallExpression(startsAt, endsAt, firstToken.ToIdentifier(), arguments.ToArray());
}
else
retval = new IdentifierExpression(firstToken.ToIdentifier());
break;
case HappyTokenKind.LiteralBool:
switch(firstToken.Text)
{
case "true":
retval = new LiteralExpression(firstToken.Location, true);
break;
case "false":
retval = new LiteralExpression(firstToken.Location, false);
break;
default:
throw new UnhandledCaseSourceException(firstToken.Location);
}
break;
case HappyTokenKind.LiteralDecimalInt32:
if(!Int32.TryParse(firstToken.Text, out intValue))
throw new InternalSourceException(firstToken.Location, "Failed to parse an Int32 from \"{0}\" _tokenKind is LiteralInt32?!?!", firstToken.Text);
retval = new LiteralExpression(firstToken.Location, intValue);
break;
case HappyTokenKind.LiteralHexInt32:
if(!Int32.TryParse(firstToken.Text, NumberStyles.HexNumber, CultureInfo.InvariantCulture.NumberFormat, out intValue))
throw new InternalSourceException(firstToken.Location, "Failed to parse an Int32 from \"{0}\" _tokenKind is LiteralHexInt32?!?!", firstToken.Text);
retval = new LiteralExpression(firstToken.Location, intValue);
break;
case HappyTokenKind.LiteralHexInt64:
long longValue;
if (!Int64.TryParse(firstToken.Text, NumberStyles.HexNumber, CultureInfo.InvariantCulture.NumberFormat, out longValue))
throw new InternalSourceException(firstToken.Location, "Failed to parse an Int32 from \"{0}\" _tokenKind is LiteralHexInt64?!?!", firstToken.Text);
retval = new LiteralExpression(firstToken.Location, longValue);
break;
case HappyTokenKind.LiteralDouble:
double doubleValue;
try
{
doubleValue = Double.Parse(firstToken.Text);
} catch(Exception e)
{
throw new InternalSourceException(e, firstToken.Location,
"Failed to parse a Double from \"{0}\" but _tokenKind is LiteralDouble?!?!", firstToken.Text);
}
retval = new LiteralExpression(firstToken.Location, doubleValue);
break;
case HappyTokenKind.LiteralString:
retval = new LiteralExpression(firstToken.Location, firstToken.Text);
break;
case HappyTokenKind.LiteralNull:
retval = new NullExpression(firstToken.Location);
break;
case HappyTokenKind.BeginTemplate:
retval = this.ParseAnonymousTemplateExpression(firstToken.Location);
break;
default:
_errorCollector.UnexpectedToken(firstToken);
throw new AbortParseException(firstToken.Location);
}
return retval;
}