"Deane Yang" wrote
Andy Little wrote:
"Matt Calabrese" wrote
I'm not going to make bad code easy to write by allowing points to be added with operator +.
You seem to be making good code more difficult to write though. :-(
I humbly disagree. He's trying to differentiate between interface and implementation, to make it easier to write good code.
You need + in the interface so users like me can write out the formulas as they see them written down. [cut]
hmm.... Geometry does define addition of points....
Not that I'm aware of. Could you elaborate? Given two points, A and B, "A+B" makes no geometric sense but "tA + (1-t)B" does. You should think of the latter as a primitive geometric operation.
err... hmm ... "tA + (1-t)B" is using '+' , Isnt it?
The fact that it can be written in terms of vector addition is an implementation detail and should be hidden from the interface.
Nonsense. '+' should be part of the interface. [cut]
Addition is pretty common e.g for curves, for piecewise integrals(e.g Simpsons rule) etc. Physical data is noisy more often then not.
If you parse these formulas carefully, you will see that they can always be written in terms of the following operations only:
point +/- vector = point vector +/- vector = vector vector */ scalar = vector
If the goal is to write good code, then please dont cooerce me to do home-made rearrangements of standard formulas to hide +. Thats a source of errors if ever there was one ;-)
You havent actually removed addition. You've just given it a non-obvious name. ;-)
No. He's removed addition of points from the interface and hidden it in the implementation.
No.. hes just changed the name . Its still in the interface., unless he's planning not to make the component_add function available to users. FWIW a reinterpret_cast to a vector looks like the easiest workaround!
I agree with this. This for me makes it easier to write good code, not harder, because it protects you from coding incorrect formulas involving points.
It certainly wastes my time trying to find workarounds or rearranging perfectly good formulae.to use '-'. More work for anyone reading or reviewing the code too. [cut]
I dont see how changing the name of the function helps. componentwise_add is an addition right?
By using a long and conspicuous name, it signals to the programmer that the formula should be checked with extra care, since the compiler cannot verify that only allowable operations are used in the formula.
Maybe it makes the programmer wonder why they didnt provide operator +. This type of code is usually written using floating point types. I would suggest making the library as simple to use as possible. regards Andy Little