Error Signalling

["Scott E. Fahlman" <Fahlman@C.CS.CMU.EDU>]

In reply to: shebs at utah-orion.UUCP (Stanley Shebs)

Regarding your comment that PCLS is "pretty sleazy most of the time"
with respect to argument checking and that "users seem to like it that
way", it would of course be allowable for any self-proclaimed subset not
to do this checking.  Whether that's among the ways in which you would
want to deviate from the standard is another question, but it's one for
your group to decide internally, since you have declared that you don't
intend to implement the full standard.  (Or am I misunderstanding the
goals of PCLS?)

Anyway, in your later note you seem to agree that requiring this
checking in the standard, except where the user has indicated that
safety is not important, is OK with you, so I guess we have no
disagreement.

    BTW, why not flush the silly numbers and use t,nil or else keyword names
    like :unsafe and :bombproof and :nuclear-qualified?  0s and 3s don't
    convey much meaning....

The thought was that the user might want to convey more information
about his preferences than would be possible in using binary-valued
switches.  A limited range of numbers seemed like the most reasonable
and least confusing solution, though it's clearly not ideal.  A number
of the more complex CLisp implementations make good use of the
multiplicity of values to fine-tune which optimizations their compiler
employs.

-- Scott