IQueryable IQueryProvider.CreateQuery(Expression expression)
{
Type elementType = TypeCoercionUtility.GetElementType(expression.Type) ?? expression.Type;
try
{
// TODO: replace with DynamicMethodGenerator.GetTypeFactory?
return((IQueryable)Activator.CreateInstance(typeof(Query <>).MakeGenericType(elementType), new object[] { this, expression }));
}
catch (TargetInvocationException ex)
{
// unwrap inner exception
throw ex.InnerException;
}
}
private object ConsumeArray(IStream <Token <ModelTokenType> > tokens, Type arrayType)
{
Token <ModelTokenType> token = tokens.Pop();
// verify correct starting state
if (token.TokenType != ModelTokenType.ArrayBegin)
{
throw new TokenException <ModelTokenType>(
token,
String.Format(ModelAnalyzer.ErrorExpectedArray, token.TokenType));
}
Type itemType = TypeCoercionUtility.GetElementType(arrayType);
// if itemType was specified by caller, then isn't just a hint
bool isItemTypeHint = (itemType == null);
IList array = new List <object>();
while (!tokens.IsCompleted)
{
token = tokens.Peek();
// consume the next item
object item;
switch (token.TokenType)
{
case ModelTokenType.ArrayBegin:
{
// array item
item = this.ConsumeArray(tokens, isItemTypeHint ? null : itemType);
break;
}
case ModelTokenType.ArrayEnd:
{
// end of the array loop
tokens.Pop();
return(this.Coercion.CoerceCollection(arrayType, itemType, array));
}
case ModelTokenType.ObjectBegin:
{
// object item
item = this.ConsumeObject(tokens, isItemTypeHint ? null : itemType);
break;
}
case ModelTokenType.Primitive:
{
// primitive item
if (!this.TryReadFilters(tokens, out item))
{
// TODO: evaluate how to ensure that filters didn't take anything
token = tokens.Pop();
item = (token != null) ? token.Value : null;
}
if (!isItemTypeHint)
{
item = this.Coercion.CoerceType(itemType, item);
}
break;
}
default:
{
// these are invalid here
tokens.Pop();
throw new TokenException <ModelTokenType>(
token,
String.Format(ModelAnalyzer.ErrorExpectedArrayItem, token.TokenType));
}
}
// establish common type
itemType = TypeCoercionUtility.FindCommonType(itemType, item);
// add item to the array
array.Add(item);
}
// end of input
throw new TokenException <ModelTokenType>(
ModelGrammar.TokenNone,
ModelAnalyzer.ErrorUnterminatedArray);
}