/// <summary>
/// ConstantExpression visit method
/// </summary>
/// <param name="c">The ConstantExpression expression to visit</param>
/// <returns>The visited ConstantExpression expression </returns>
internal override Expression VisitConstant(ConstantExpression c)
{
if (c.Value == null)
{
this.builder.Append(UriHelper.NULL);
return(c);
}
// DEVNOTE:
// Rather than forcing every other codepath to have the 'Try...' pattern for formatting,
// we catch the InvalidOperationException here to change the exception type.
// This is exceedingly rare, and not a scenario where performance is meaningful, so the
// reduced complexity in all other call sites is worth the extra logic here.
string result;
try
{
result = LiteralFormatter.ForConstants.Format(c.Value);
}
catch (InvalidOperationException)
{
if (this.cantTranslateExpression)
{
// there's already a problem in the parents.
// we should just return here, because caller somewhere up the stack will throw a better exception
return(c);
}
throw new NotSupportedException(Strings.ALinq_CouldNotConvert(c.Value));
}
Debug.Assert(result != null, "result != null");
this.builder.Append(result);
return(c);
}
internal override Expression VisitConstant(ConstantExpression c)
{
string result = null;
if (c.Value == null)
{
this.builder.Append(UriHelper.NULL);
return(c);
}
else if (!ClientConvert.TryKeyPrimitiveToString(c.Value, out result))
{
throw new InvalidOperationException(Strings.ALinq_CouldNotConvert(c.Value));
}
Debug.Assert(result != null, "result != null");
this.builder.Append(System.Uri.EscapeDataString(result));
return(c);
}