On Tue, 6 Mar 2007, Andre van Tonder wrote:
> On Tue, 6 Mar 2007, Aubrey Jaffer wrote:
>
>> By requiring phased processing of libraries, R5.92RS has
>> disenfranchised "pure interpreters", apparently for the sake of
>> macros.
>
> This is not accurate. At least one of the reference implementations of
> libraries and macros, at
>
> http://www.het.brown.edu/people/andre/macros/index.html
>
> runs as is in both the MzScheme and the Petite Chez interpreters' REPLs,
> using only the ability of these implementations to interpret vanilla r5rs
> code.
To be concrete, the implementation defines a procedure called $repl, so that
one can type the following sequence of forms into one's interpreter of choice
to execute the example in the r6rs document, with the correct semantics, as
follows:
($repl
'(
(library (my-helpers id-stuff)
(export find-dup)
(import (r6rs))
(define (find-dup l) .......))
($repl
'(
(library (my-helpers value-stuff)
(export mvlet)
.........)))
($repl
'(
(library (let-div)
(export let-div)
.......)))
($repl
'(
(program
(import (let-div) (r6rs))
(let-div 5 2 (q r) (+ q r))
)))
==> 3
Modifying an interpreter so that one does not have to type the
($repl '( --- )) each time should be trivial.
Andre
Received on Tue Mar 06 2007 - 14:39:19 UTC