When I have a lot of functions to define that may be recursive and even mutually recursive, I frequently use define in stead of explicit letrec. With a lot of variables to be bound, the boundlist of letrec may become incomprehensibly long.
Jos -----Original Message----- From: users-boun...@racket-lang.org [mailto:users-boun...@racket-lang.org] On Behalf Of Grant Rettke Sent: domingo, 10 de julio de 2011 17:37 To: Eli Barzilay Cc: users Subject: Re: [racket] why do I get undefined ,when using internal definition? On Sun, Jul 10, 2011 at 9:53 AM, Grant Rettke <gret...@acm.org> wrote: > On Sun, Jul 10, 2011 at 1:49 AM, Eli Barzilay <e...@barzilay.org> wrote: >> `define' is defining a potentially recursive value, so that >> >> (define (loop) (loop)) >> >> works as you expect. In simple terms, you can think about an internal >> define as something that expands to a `letrec'. So what you wrote is >> basically the same as >> >> (define (make-color color) >> (letrec ([color color]) >> ...)) > > In what kind of situations would you use internal define over letrec? Sorry I mean using define rather than a letrec explicitly. _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
