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DRAFT of the Revised Revised Report
(define (number-of-special-forms-in-standard date)
(expt 2 (date->number date)))
Named let corresponds to named-lambda in the same way that let
corresponds to lambda. If argument list destructuring is not a
problem for let, it is not a problem for named let. If it is, the
only "destructuring" allowed in lambda is for &rest arguments (dot
notation). The syntax for LET can be extended to accept rest
Note: Each of the subforms of the binding list of a let must be a
list whose CAR is the identifier and whose CADR is the expression
whose value the identifier will receive. Thus the syntax can be
extended to the following:
(let ((<identifier 1> <exp 1>)
(<identifier n> <exp n>)
<rest identifier> ; Note: no parens
<rest exp 1>
<rest exp m>)
The rest identifier can be recognized by not being in a list,
and all forms following it are the expressions whose values will be
collected into the &rest list.
I'm not advocating for this extension in the standard, but any
implementation which wants named-let can easily extend the syntax for
let and named-let so that this "destructuring" is provided.
You may be right in that this means that there are 2 special
forms with the same keyword, but that's alright with me. I don't want
to have to remember 50 thousand different identifiers which are
"special" to ths system, and I cannot use as identifiers in portable
code since I don't know what happens in all implementations when a
lambda-parameter attempts to shadow them.
I have no problems recognizing one-armed ifs. They only
appear in the middle of sequences (sorry, begins) and indentation
allows me to see whether there is a second arm or not.