usage statement on builtin functions

[Paul Kienzle]

On Nov 13, 2005, at 7:56 AM, William Poetra Yoga H wrote:

> --- Paul Kienzle <address@hidden> wrote:
>
> > On Nov 12, 2005, at 11:34 PM, William Poetra Yoga H wrote:
> >
> > > Btw, is my usage of @sc{} appropriate?
> > > Also, can I replace usage(...) above with this?
> > >
> > >   help("isunix");
> > >   error("");
> >
> > No.  This forces output to the terminal even if you are in
> > an environment such as try ... catch or eval(code,catch).
>
> Well then, I think it would be nice if we can make function files 
> behave like
> built-in functions: if it takes an argument and we don't specify one, 
> it would
> print the help message and exit with an error. Maybe we should have a
> specialized function to do this?

I agree that builtin functions should behave like scripts. However
I prefer the script behaviour of printing a one-line usage statement
when functions are used incorrectly rather than dumping a screenful
of docs.

Making this change to Octave would require substantial effort, so
I wouldn't start it before asking John if he agrees.

The implementation should also consider a possible future IDE.
An IDE should be able to introspect on the function when providing
feedback to the user on what parameters it is expecting.  The
usage statement is a simplified version of this.

- Paul