Re: SICP stream question

[Keith Wright]

> Cc: address@hidden
> 
> Is define-macro portable across the various scheme implementations?

No.

> The only thing I could find in r5rs was define-syntax, which I
> couldn't get to work.

This works for me

file scheme-test:

    ; orignal definition
    ; (define cons-stream
    ;   (procedure->macro
    ;    (lambda (x env) `(cons ,(cadr x) (delay ,(caddr x))))))
    
    (use-modules (ice-9 syncase))
    (define-syntax cons-stream
      (syntax-rules ()
        ((_ head tail) (cons head (delay tail))) ))
    
    <All the functions you wrote>

guile> (load "scheme-test.scm")
guile> (map (lambda (n) (stream-ref primes n)) '(0 1 2 3 4 5 12))
(2 3 5 7 11 13 41)

-- 
     -- Keith Wright  <address@hidden>

Programmer in Chief, Free Computer Shop <http://www.free-comp-shop.com>
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