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
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