[r6rs-discuss] Interpreters need not apply?

[Andre van Tonder]

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