On 25 May 2011, at 04:51, Matthew D. Swank wrote: > I have implemented a small fexpr interpreter in Common Lisp based on > Kernel http://web.cs.wpi.edu/~jshutt/kernel.html. Right now it's a Lisp > 1, but I am considering trying to make it a more idiomatic extension of > Common Lisp by making it a Lisp 2. > > Part of the Lisp 2-ness of the Common Lisp evaluator is that the car of > a form must name a function, macro, or special form. This name is either > a symbol bound in the function name space, or a lambda expression. > However, Kernel just requires the car evaluate to a combiner (this is > what Kernel calls a generic operator). Obviously, in a Lisp 2, a symbol > would evaluate to the value bound to it in the function name space. > However, consider the following: > > ((returns-a-function) arg arg ...) > > Would it be reasonable to allow this as a legal form as well? > > I'm not arguing Common Lisp should work this way, but I seems to make > sense in the context of a Kernel like evaluator.
_If_ (returns-a-function) indeed returns a function, then this could be ok. But what if it doesn't return a function? What if it is a macro that returns just a symbol? Do you want to risk that ((return-something) ...) has a different meaning than (funcall (return-something) ...)? This is potentially confusing and could lead to code that is hard to debug... Pascal -- Pascal Costanza The views expressed in this email are my own, and not those of my employer. _______________________________________________ pro mailing list pro@common-lisp.net http://lists.common-lisp.net/cgi-bin/mailman/listinfo/pro