[Gretl-devel] omit bug

[Allin Cottrell]

On Sat, 24 May 2008, Sven Schreiber wrote:

[ first, about cating 1x1 matrices to scalars, to which I'll reply 
later, then... ]

> > > BTW, on various occasions I noticed that arithmetic 
> > > expressions cannot always be used in place of simple 
> > > variables. But sometimes it does seem to work. Is there some 
> > > rule when it should work, or is it sheer luck when it does?
> > 
> > In general, arbitrary arithmetic should work for arguments to 
> > built-in functions (or user-defined functions for that 
> > matter), while it's not very likely to work for arguments to 
> > straight "commands".
> 
> In principle I think I understand, but I'm not sure the 
> demarcation between commands and functions is very clear in 
> gretl. What would that 'pvalue' thing be for example?

For the most part the distinction is pretty clear: a function is 
something where all the arguments are wrapped in parentheses and 
separated by commas, and a command is everything else.  But there 
are a few hybrid cases, and "pvalue" is one such.  Since we have a 
perfectly good pvalue function with the same semantics, we 
implement the "command" form by composing and executing a call to 
"genr"; this gives more flexibility on the form of the arguments.

Allin.