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Re: [Chicken-users] handling the undefined value
From: |
Felix |
Subject: |
Re: [Chicken-users] handling the undefined value |
Date: |
Wed, 17 Nov 2010 23:59:09 +0100 (CET) |
From: Jörg "F. Wittenberger" <address@hidden>
Subject: [Chicken-users] handling the undefined value
Date: Wed, 17 Nov 2010 20:56:29 +0100
>* The handling of -extend has changed in a way I do not yet completely
>understand. Before I could define some syntax there and it would be
>available during the compile. Apparently that's no longer the case.
>Now, since I used several different ways to convince chicken to compile
>some modified syntax, I'm not yet sure in which cases it will work, and
>which will break now.
>Intentionally?
Of course. It is my secret plan to make things hard for you. So far
you've done well, but I still have some mean tricks up my sleeve ...
>* I have a piece of code (which could be expressed in a much more modern
>form, considering that there's a srfi-39 now) -- but the possible
>improvement is not my point. It better would still work, but it raises
>a strange error right now and I have a work around, which is even more
>strange (in a way, though I guess this hints towards an optimisation
>error or alike):
>Module A exports (just) 'root-object' (from these 3):
>(define *root* #f)
>(define (load-root . arg)
> (and-let* ((f (if (pair? arg) (car arg) (load-object ... ... ...))))
> (set! *root* (object-identifier f))
> (object-identifier f)))
>(define (root-object . x) (or *root* (apply load-root x)))
>Module B (importing A) calls (root-object)
>(root-object) =3D> #f
>after a while:
>(root-object) =3D> #<lambda info (A#root-object . x6617)>
Very strange indeed. What is the value of *root* in this case?
Do you use unsafe operations or low-level operations or the FFI
for `load-object' or `object-identifier'?
cheers,
felix
- [Chicken-users] handling the undefined value, F. Wittenberger, 2010/11/17
- Re: [Chicken-users] handling the undefined value, Felix, 2010/11/17
- Re: [Chicken-users] handling the undefined value,
Felix <=
- Re: [Chicken-users] handling the undefined value, F. Wittenberger, 2010/11/18
- Re: [Chicken-users] handling the undefined value, Felix, 2010/11/19
- Re: [Chicken-users] handling the undefined value, F. Wittenberger, 2010/11/19
- Re: [Chicken-users] handling the undefined value, Felix, 2010/11/20
- [Chicken-users] NE [[not exactly]]: handling the undefined value, F. Wittenberger, 2010/11/21
- [Chicken-users] Re: NE [[not exactly]]: handling the undefined value, Felix, 2010/11/22
- Re: [Chicken-users] handling the undefined value, F. Wittenberger, 2010/11/22
- Re: [Chicken-users] handling the undefined value, Felix, 2010/11/24
- Re: [Chicken-users] handling the undefined value, John Cowan, 2010/11/24
- Re: [Chicken-users] handling the undefined value, F. Wittenberger, 2010/11/25