internal static IEnumerable <Instruction> CompileImplicitConversion(
RedwoodType from,
RedwoodType to)
{
if (to == null)
{
// If we have a null destination, this shouldn't
// even get called; we will be resolving it closer
// to runtime
throw new ArgumentException("Cannot convert to dynamic type");
}
if (from == null)
{
return(new Instruction[]
{
new DynamicConvertInstruction(to)
});
}
else if (to.IsAssignableFrom(from))
{
// In this case, we are a subtype or the correct type
// so we don't need to do anything
return(new Instruction[0]);
}
else if (from.HasImplicitConversion(to))
{
if (from.CSharpType == null)
{
if (!from.HasImplicitConversion(to))
{
throw new NotImplementedException();
}
int slot = from.implicitConversionMap[to];
return(new Instruction[]
{
new LookupDirectMemberInstruction(slot),
new InternalCallInstruction(new int[0])
});
}
// This call won't work on a RedwoodType in the compile phase
// because the static lambdas aren't populated yet
return(new Instruction[] {
new CallWithResultInstruction(
RuntimeUtil.GetConversionLambda(from, to)
)
});
}
else
{
// Cannot convert between the types
throw new NotImplementedException();
}
}