| [m2t-dev] Re: int and long |
Laurent,
Skyping was nice (I got to understand many "how to"s :p) yet ... I forgot to ask about this particular issue : primitive types in the backend for Integer, Short, ... (actually working with OCL now, and they have Integers too).Did you plan to have those primitive types reflected in the backend? I'm still available on Skype though only for chatting at the moment (I can ask for a room if you think this would be easier).
Okay, let me exlain again.Yes, OCL has Integer, but no Long - there is exactly one type for numbers without a fraction part, right? And these are currently represented as Long in the backend. So the OCL type "Integer" is represented by LongType. There should *never ever* be an instance of java.lang.Integer in the backend - they must be converted to Long, as for example the Java calling code does. Otherwise you run into all kinds of difficulties, as you found out.
That should settle the OCL compatibility part.It would be something else altogether if you needed to *differentiate* between functions taking int and long parameters. So far I never came across a convincing use case for that, but if you have one, I will not be too difficult to convince ;-) --> What do you need the differentiation for?
Another somewhat related issue I stumbled upon today : you have defined many primitive operations within the syslib. Among those is the "operatorEquals" defined on Object parameters... What to do in a case such as "1 * 5 == 5"?Multiplication will return a Double, 5 is obviously an Integer. <anydouble>.equals(<anyinteger>) _cannot_ return true, which is however the expected result. What is the expected way of handling such a case with the backend? Do we need to convert every parameter to the same type before calling operatorEquals?
The multiplication of two Long numbers returns a Long value. If your specific situation (or your language in general) needs to treat Long and Double as equal, feel free to map the "==" operator of your language to some other library function that performs the type casts as needed. But I view this as specific to your language - you can implement special behavior for it, but it will probably not go into the syslib implementations.
- Arno -- Arno Haase Langemarckstr. 16 53227 Bonn Mobil: +49 160 98525085 Tel: +49 228 9654443 Fax: +49 228 9654448
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