Re: Rest and patterns

[Sebastian Egner <sebastian.egner@xxxxxxxxxxx>]

David Van Horn wrote:
> The recent discussion over binding the "rest"
of the values seems to me to be 
> a proposal for a (very small) pattern language, and an extension of
`let' to 
> allow for patterns in the LHS of each clause.
>
> So, perhaps this SRFI would be better suited by developing a thorough
pattern 
> language, which `let' could be extended to use.  The "values"
part of this 
> proposal would simply fall out of such an approach.

The thought crossed my mind. In the
end I decided that the problem I really 
want to solve with this SRFI is making
multiple values as convenient as they
can get in Scheme. Unfortunately, a
general pattern language contributes
only very little towards this goal,
so I dropped it quickly.

When chosing the syntax to propose,
however, I did watch out not to close the
door on other possible extensions too
early. In particular, Eli Barzilay's LET
from Swindle extends for local lambda-expressions.
This is still fully compatible
with the current SRFI-71, with the restriction
that procedure must not be called
VALUES.

Sebastian.

srfi-71-request@xxxxxxxxxxxxxxxxx 18-05-2005 22:47

To:        srfi-71@xxxxxxxxxxxxxxxxx         cc:        (bcc: Sebastian Egner/EHV/RESEARCH/PHILIPS)         Subject:        Rest and patterns         Classification:

The recent discussion over binding the "rest"
of the values seems to me to be 
a proposal for a (very small) pattern language, and an extension of `let'
to 
allow for patterns in the LHS of each clause.

So, perhaps this SRFI would be better suited by developing a thorough pattern
language, which `let' could be extended to use.  The "values"
part of this 
proposal would simply fall out of such an approach.

Or, on the other hand, perhaps this SRFI should remain within it's current
scope, but in that case I would suggest leaving the extension of `let'
in such 
a way that it is still possible to extend `let' to use patterns in the
future. 
  For this reason, I suggest keeping the `values' keyword that Neil
W. Van 
Dyke recently argued against.

David