Re: add-relative-load-path ? - scm_add_load_path too?

[Ian Hulin <ian@hulin.org.uk>]

Hi Andy, Ludo,

I've just seen the add-load-path scheme function in the new git
documentation.

Please, please, pretty please can we have a scm_add_load_path API
equivalent callable from C/C++? The LilyPond initialization code
currently does disgusting things like faking
(eval (set! %load-path cons ( <blah> %load-path ) ) )

a call such as

(scm_add_load_path (scm_from_locale_string ("<blah") );

would look far more civilized, and  I'd be able to take out the
current hack, complete with the comments containing shudders of disgust.

Cheers,

Ian Hulin

On 08/01/12 15:14, Andy Wingo wrote:
> Hi all,
> 
> In the following thread:
> 
> http://thread.gmane.org/gmane.lisp.guile.user/8298/focus=8403
> 
> there was a concern that it's difficult to set up the load path
> for simple one-off scripts.
> 
> I had a proposal that we add something like this:
> 
> (define-syntax add-relative-load-path (lambda (x) (syntax-case x
> () ((_ path) (string? (syntax->datum #'path)) (let* ((src
> (syntax-source #'x)) (current-file (or (and src (assq-ref src
> 'filename)) (error "Could not determine current file name"))) 
> (vicinity (dirname (canonicalize-path current-file))) (path-elt
> (in-vicinity vicinity (syntax->datum #'path)))) #`(eval-when
> (compile load eval) (set! %load-path (cons #,path-elt
> %load-path))))))))
> 
> Then in your script you would (add-relative-load-path ".").
> 
> Maybe we need an `add-to-load-path' form that handles the
> eval-when, actually, so it would be
> 
> (add-to-load-path (dirname (current-source-filename)))
> 
> or something like that.  (We'd have to define
> current-source-filename as well, in terms of
> current-source-location.)
> 
> What do folks think?  Is it work it?
> 
> Andy