-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 14-12-11 21:19, Harry Spier wrote: > Dear list members, > > In the Racket Guide 16.1.7 Extended Example: Call-by-Reference > Functions it shows how with macros to set up call by reference > versions of Racket functions. > > I'm a little bit confused on why for the example, the macro (swap > x y) was used as the example function to turn into a > call-by-reference function, since doesn't the macro (swap x y) > already act like a call-by-reference function.
I think the point is to contrast (define (f x y) (swap x y)) with (define-cbr (f x y) (swap x y)). That first f is a function that swaps its local arguments with no change to the outside world, while the second f is a macro (IIUC) that mutates its real (for lack of a better term (on my part)) arguments, through the macro magic of define-cbr. Marijn -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk7ptigACgkQp/VmCx0OL2yZXgCfcssK4HvrAHyr4dKYEIXAXbrG e3kAoIh30Ojc47p16Jtb5ksxyLixFRBS =0lMo -----END PGP SIGNATURE----- _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
