On 10 Nov 2011, at 00:11, Andy Wingo wrote:
> On Thu 04 Aug 2011 10:56, Hans Aberg writes:
>
>> I try to understand how Guile transforms 'letrec' (returning to the
>> topic of an earlier post on this list).
>
> `letrec' is translated to various things, some of which are not Scheme.
> As Ludo n
On Thu 04 Aug 2011 10:56, Hans Aberg writes:
> I try to understand how Guile transforms 'letrec' (returning to the
> topic of an earlier post on this list).
`letrec' is translated to various things, some of which are not Scheme.
As Ludo notes, see the "Fixing Letrec" paper by Dybvig et al.
Andy
Just FYI, I found a source saying that R5RS defines (though I could not find it
there) 'letrec' via this transformation (which also answers my question):
(letrec ([x1 e1] ... [xn en]) body)
~>
(let ([x1 undefined] ... [xn undefined])
(let ([t1 e1] ... [tn en])
(set! x1 t1)
..
Hello!
Hans Aberg skribis:
> So letrec is transformed to something else. What might that be?
I believe you’re seeing the “Fixing letrec” algorithm in action (see the
paper of that name by Dybwig et al.)
Thanks,
Ludo’.
