On Mon, 28 Feb 2011 16:38:34 -0500, Don <nos...@nospam.com> wrote:
spir wrote:
Just don't use them!
You don't have that option. At least, if you're a library developer, you
don't. (I'm a bit sick of people saying "you don't have to use it if you
don't want to" in language design. If it is in the language, you don't
have a choice. You will encounter it).
encounter *reading* it or encounter *using it*? You shouldn't ever have
to use named parameters if you don't want to. Just like you can specify
all defaulted parameters, or specify all template args when calling
templated functions.
I could live without named parameters (obviously!), but I certainly think
reading a call with named parameters can be much easier with the parameter
names than without, and I don't think you could ever say the opposite
(that name-less parameters would be clearer).
There are a couple of things that I really, really don't like about the
names argument idea:
1. It makes parameter names part of the API.
Providing no way for the function writer to control whether it is part
of the API or not, and especially, doing it retrospectively, strikes me
as extremely rude.
2. It introduces a different syntax for calling a function.
foo(4, 5);
foo(x: 4, y: 5);
They look different, but they do exactly the same thing. I don't like
that redundancy.
I look at it similarly to IFTI:
foo(T)(T t) {...}
foo(1);
foo!int(1);
both mean the same, the int is optional.
Note that the library developer of foo has no way to restrict you from
using either form. One is simply a clearer way of saying the other.
In essense, the parameter names are ALREADY an essential part of the API.
If we didn't name the parameters (entirely possible with .di files!), how
shitty would programming be?
Especially since, as far as I can tell, the named arguments are just
comments (which the compiler can check).
If so, a syntax like this would be possible, with no language change at
all:
pragma(namedarguments); // applies to whole module
foo(/*x*/ 4, /*y*/ 5);
---> if a function parameter has a comment which forms a valid
identifier, it's a named parameter.
There is a feature that isn't available via comments, parameter reordering:
foo(y: 5, x: 4);
Who in their right mind wants to do this, right? Well, consider you use
two different libraries, and in one library the y is always the first
parameter, and in another the x is always the first parameter (yes, I've
seen shit like this). Calls to the separate libs might be a nightmare of
continuous documentation referencing.
But if you can just always say "x is first", then the calls are easy to
read and write, and completely unambiguous.
But I still don't see the need for this feature. Aren't people using
IDEs where the function signature (with parameter names) pops up when
you're entering the function, and when you move the mouse over the
function call?
Dunno, vim doesn't do that for me currently. Also, if reviewing code on
github, there is no ide.
-Steve
