On Mon, 16 Feb 2004 13:32:13 -0700, Jack Hamilton <JackHamilton@FIRSTHEALTH.COM> wrote:

>"Chang Y. Chung" <chang_y_chung@HOTMAIL.COM> wrote: > >>(1) in both the case, it is critical to check if study is empty. >Since >>when it is empty, you get a stransge value for outfile, also -- I >think >>this means that study is a required parameter. Consider making it >>positional also. > >Why so? > >I used to use positional parameters, and now I almost never do if >there's more than one parameter. Named parameters give a clue what the >parameters are trying to do.

Hi, Jack,

You are absolutely correct. There is no reason not to stick to named parameters only -- I agree with you.

Having said that, let me try to defend the opinion, if I may. I just thought, in some cases, the code reads better if you make required parameters as positional parameters. For example, if you are writing a macro called %sortBy(by=, options=), I just thought it would be nicer to be able to write:

%sortBy(VarA),

instead of the following which is kinds of redundant,

%sortBy(by=VarA).

Besides, you can do %sortBy(by=Vara), if you want to, even when the "by" is a positional parameter.

The key is that if a macro parameter is required, then the parameter value should be such a critical one that the macro name itself should give intuitive enough clue about what is required. And if so, then we may get a code that is, in fact, more easily understood by humans.

But, again, I guess what is "intuitive" depends, so it may be better to stick to a simpler (and better) coding style. On top of it, I have no doubt about your experience and wisdom. So, ... I have no problem writing macros without positional parameters :-)

Cheers, Chang