Re: [q-lang-users] Special values or failing functions

[Albert G. <Dr....@t-...>]

Ok, I just committed the necessary changes to implemented _FAIL_, but I
still need a nice and useful example of _FAIL_ for the documentation.
Any ideas?

About the name: I sticked to '_FAIL_' after all. I know that it sticks
out like a sore thumb, but that's actually intended. :-)

Alexander Nickolsky wrote:
> I mean 'fail' acts as if the current rule's left side did not match.
> _FAIL_ is a regular function.

Note that 'fail' is a "regular function", too. In fact, if you take a
look at the latest cvs sources you'll see that both fail and _FAIL_ are
implemented in a completely analogous fashion. They both just signal a
special kind of exception which is then handled in the guts of the
interpreter by aborting either just the current equation or all
remaining equations, respectively.

Albert

-- 
Dr. Albert Gr"af
Dept. of Music-Informatics, University of Mainz, Germany
Email:  Dr....@t-..., ag...@mu...
WWW:    http://www.musikinformatik.uni-mainz.de/ag