Benjamin Franksen wrote:
Brian Hulley wrote:
ith = Data.Array.IArray.(!)
Sorry, but I can't see the problem here. Why can't the editor offer the operator as '!' in the list of options, and if the user selects it insert both '(' and ')' at the right places (i.e. before the module name and after the operator)? Is there some unwritten law that forbids editors or IDEs to insert stuff at positions other than the current cursor position?
I hadn't thought of that - I've now decided to just use the existing syntax here.
Generally speaking, I would always hesitate to change the language so it better suits programming tools(*). It is the tools which should adapt to the language, even if that means the programmer has to find new ways of suporting the user (and the language). The most important reason being that code is more often read than written.
My motivation for the change was that it would better suit the human user of the programming tool, though in this particular instance you and Henning have convinced me that the original syntax was better after all.
At the danger of becoming completely off-topic now (sorry!), I have to say that I find /both/ versions ugly and unnecessarily hard to read. My personal solution is to generally avoid qualified imports.
How does this solution scale? Surely it's only lucky if people happen to choose names that don't clash with those of other modules?
I use it only if absolutely necessary to disambiguate some symbol, and then just for that symbol. I am aware that there is an opposing faction here, who tries to convinve everyone that qualified import should be the standard (and the actual exported symbols --at least some of them-- meaningless, such as 'C' or 'T').
Although C and T are in themselves meaningless, the name of the module itself is not. As I understand it, this convention makes the module name carry the meaning so you use Set.T instead of Set.Set where the meaning is duplicated (a rather uneasy situation) in both the module name and type name.
I think such a convention is inappropriate for a functional language (especially one with user defined operators). There simply is no natural 1:1 correspondence between data type declaration and functions acting on that data built into the language, as opposed to e.g. OO languages. Extensibility in the functional dimension, i.e. the ability to arbitrarily add functions that operate on some data without having to change the code (module) that defines the data, is one of the hallmarks of functional programming, as opposed to OO programming.
If you have an abstract data type then it *is* like an object (though in a potentially more powerful way than in OOP) because there is no other way to manipulate values of that type. If the type is not abstract, the advantage of calling it T is just that it avoids naming it twice (by type name and module name) in the situation where you want to not worry about name clashes with constructors of other types.
However, nothing prevents us from offering two interfaces (visible modules), one where the data type is abstract ("client interface") and a different one where it is concrete ("extension interface")
You can still call both types T... :-) Regards, Brian. -- Logic empowers us and Love gives us purpose. Yet still phantoms restless for eras long past, congealed in the present in unthought forms, strive mightily unseen to destroy us. http://www.metamilk.com