// <summary>
// Generates function definition or returns a cached one.
// Guarantees type match of declaration and generated parameters.
// Guarantees return type match.
// Throws internal error for functions without definition.
// Passes thru exceptions occured during definition generation.
// </summary>
internal DbLambda GenerateFunctionDefinition(EdmFunction function)
{
Debug.Assert(function.IsModelDefinedFunction, "Function definition can be requested only for user-defined model functions.");
if (!function.HasUserDefinedBody)
{
throw new InvalidOperationException(Strings.Cqt_UDF_FunctionHasNoDefinition(function.Identity));
}
DbLambda generatedDefinition;
// Generate the body
generatedDefinition = ExternalCalls.CompileFunctionDefinition(
function.CommandTextAttribute,
function.Parameters,
this);
// Ensure the result type of the generated definition matches the result type of the edm function (the declaration)
if (!TypeSemantics.IsStructurallyEqual(function.ReturnParameter.TypeUsage, generatedDefinition.Body.ResultType))
{
throw new InvalidOperationException(
Strings.Cqt_UDF_FunctionDefinitionResultTypeMismatch(
function.ReturnParameter.TypeUsage.ToString(),
function.FullName,
generatedDefinition.Body.ResultType.ToString()));
}
Debug.Assert(generatedDefinition != null, "generatedDefinition != null");
return(generatedDefinition);
}
internal static bool IsStructurallyEqualOrPromotableTo(TypeUsage fromType, TypeUsage toType)
{
if (!TypeSemantics.IsStructurallyEqual(fromType, toType))
{
return(TypeSemantics.IsPromotableTo(fromType, toType));
}
return(true);
}
internal static bool IsValidPolymorphicCast(TypeUsage fromType, TypeUsage toType)
{
if (!TypeSemantics.IsPolymorphicType(fromType) || !TypeSemantics.IsPolymorphicType(toType))
{
return(false);
}
if (!TypeSemantics.IsStructurallyEqual(fromType, toType) && !TypeSemantics.IsSubTypeOf(fromType, toType))
{
return(TypeSemantics.IsSubTypeOf(toType, fromType));
}
return(true);
}
internal DbLambda GenerateFunctionDefinition(EdmFunction function)
{
if (!function.HasUserDefinedBody)
{
throw new InvalidOperationException(Strings.Cqt_UDF_FunctionHasNoDefinition((object)function.Identity));
}
DbLambda dbLambda = ExternalCalls.CompileFunctionDefinition(function.CommandTextAttribute, (IList <FunctionParameter>)function.Parameters, this);
if (!TypeSemantics.IsStructurallyEqual(function.ReturnParameter.TypeUsage, dbLambda.Body.ResultType))
{
throw new InvalidOperationException(Strings.Cqt_UDF_FunctionDefinitionResultTypeMismatch((object)function.ReturnParameter.TypeUsage.ToString(), (object)function.FullName, (object)dbLambda.Body.ResultType.ToString()));
}
return(dbLambda);
}
