On Wed, Feb 16, 2005 at 01:55:31PM -0600, Patrick R. Michaud wrote:
: And to
: anticipate the followup question of "Well, why not make features such
: as junctions into optional modules?", I think a partial answer is that
: features like these really need deep language support to work
: effectively in their complex applications. Otherwise we'd just
: stick with Perl 5. :-)
That, and we'd like a novice to be able to write
given $x {
when 1 | 2 | 3 {...}
when 4 | 5 | 6 {...}
}
without having to know there are junctions there underneath. Forcing
them to cargo-cult a "use junctions" declaration merely to get switch
alternatives would not solve any problems I can think of. Nor would
inventing a separate switch syntax for alternatives be appropriate when
we can make junctions work for that in a semi-orthogonal fashion. As I
said elsewhere, the training wheels probably belong on the variable's
type checking, not on the underlying type space. Variable types are
*views* into the actual underlying object types bound to the variable,
and so variable types can place arbitrary restrictions on the use of
those underlying general types.
Larry
