On 15/01/12 5:57 PM, Robert Jacques wrote:
On Sun, 15 Jan 2012 07:36:53 -0600, Alex Rønne PetersenThoughts?In no particular order: 1) Adding ref to the call site is lexically similar to Hungarian notation and has all the drawbacks and advantages thereof. I know invoking Hungarian notation is almost an invocation of Godwin's law when it comes to programming syntax discussions, but Hungarian notation was introduced for a reason; there was a time when for large software projects it dramatically increases code comprehension (and thus quality) for the code reviewer and/or code maintainer. And that argument still stand today for anyone _not_ using a modern IDE. The primary reason Hungarian notation is disparaged today is that IDEs evolved beyond emacs, vim and notepad. Once they could tell the programmer with a tooltip what every variable's type was, the need to encode the type in the variable name vanished. Or more to the original point, modern IDEs already list function parameter's type and type modifiers (i.e. aka) as you type the function in so it's _always_ obvious what is ref/const/etc and what is not. And for the code reviewer, ref parameters could be auto highlighted/underlined/etc to easy their job. Yes, this issue does need to be addressed, but I don't think that this is fundamentally a language problem; it more a lack of modern tools for D. That reminds me, I need to check out the latest revision of Visual D. :)
A fair point, but: a) D doesn't have much in terms of *free* highly-featured IDEs. b) Even if it did, lots of people still use emacs/vim.c) That does not help when glancing at code to find where a variable is modified.
2) It is perfectly possible to write functions in D that require
explicit demarcation at the call site:
int foo( int* v ) { return *x; }
int y;
int z = foo(@y);
True, but these aren't the same. Pointers can be reseated, ref parameters cannot. Pointers may also be null, encouraging needless null pointer checks.
3) Mandating ref at the call is currently how C# handles reference parameters. Anytime someone suggests a feature from another language, particularly C# or Java, two questions are immediately raised in my mind. 3a) Does the asker simply want D to be more like language X?
Perhaps, perhaps not. I think it is better to evaluate a suggestion on its merit and not on the suggester's motivation.
3b) What do programmers experienced in X and in D/C++/C/etc think about that particular feature (good/bad/ugly)?
Mandated ref is well-received in C# as far as I'm aware.I also know that people dislike using reference parameters in C++ due to the lack of visibility at the call site (causing them to use pointers).
