Re: Lazy catch behaviour

[Neil Jerram]

>>>>> "Marius" == Marius Vollmer <address@hidden> writes:

    Marius> `lazy-catch' is a bit wierd, true.  If we can find another
    Marius> mechanism that does its job in a cleaner way, we should
    Marius> probably replace it.  In the mean-time, we should make
    Marius> sure that `throw' does not return, ever.  If `throw' does
    Marius> return, it should throw an error.

I don't have time right now to work out how to do this in the code.
But I propose adding this note to the reference manual documentation
for lazy-catch:

@strong{Note:} It is debatable whether the second point is actually a
desirable feature, as it makes the local behaviour of a @code{throw}
expression dependent upon the type of catch (normal or lazy) that
handles it.  Consequently, the returnability of @code{lazy-catch} may be
removed in a future Guile release, and it would be unwise for Scheme
programs to rely on this characteristic.

Does that sound OK?  (The "second point" referenced says "If the
handler returns normally --- i.e. does not @emph{itself} throw an
exception --- then the @code{throw} expression returns normally to its
caller with the handler's value.")

        Neil