Re: Loading a module before and after adding a load path

[Noah Lavine]

Hello,

I see what you are trying to do, and I agree that it should be possible. I have set up the same situation as you: trying to load a module, failing, adding it to my path, trying again, and failing again. Here's what I've figured out:

- resolve-module fails on the module, when I think it should succeed. that's because

- try-autoload-module fails on the module, when again I think it should succeed. and that's because

- autoload-done-or-in-progress? returns #t for the module, when I think it should return #f. specifically, the module is marked as done, and therefore try-module-autoload won't look for it any more.

- the module was marked as autoloaded because that's what try-module-autoload does: it *always* marks its module as autoloaded, even if it wasn't found.

As a workaround, remove your module from the list "autoloads-done". (actually, there will be a pair in that list, where the cdr of the pair is the name of the module as a string. remove that.)

In the long term, Andy and Ludo, what is the right way to fix this? Should try-module-autoload not mark unfound modules as autoloaded? Or maybe there should be a special function that says "retry this module, starting from the beginning". Maybe it could even be part of reload-module.

Best,

Noah

On Fri, Jan 18, 2013 at 11:15 PM, Diogo F. S. Ramos <address@hidden> wrote:

Nala Ginrut <address@hidden> writes:

> Why you need to load the module without giving its path?

Sorry, I should have added some more context.

While I'm working with the REPL, sometimes I forget to add the path to a
module before trying to use it. It's a mistake. So, after trying to load
the module with `use-modules', and failing, I remember that I have to
add the path to the module. So I add the path to the module with
`add-to-load-path' and I try again to evaluate
`use-modules'. Unfortunately it does not load it and I'm stuck. To fix
it, I end up restarting the REPL and adding the path _before_ trying to
load it, as it's the right way to do it.

Here is an example with my typical mistake:

$ cat /tmp/foo/bar.scm
(define-module (foo bar))

(define-public (hello)
  (display "hello, world")
  (newline))
$ guile
GNU Guile 2.0.5-deb+1-1
Copyright (C) 1995-2012 Free Software Foundation, Inc.

Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'.
This program is free software, and you are welcome to redistribute it
under certain conditions; type `,show c' for details.

Enter `,help' for help.
scheme@(guile-user)> (use-modules (foo bar))
While compiling _expression_:

ERROR: no code for module (foo bar)

scheme@(guile-user)> (add-to-load-path "/tmp")
scheme@(guile-user)> (use-modules (foo bar))
While compiling _expression_:

ERROR: no code for module (foo bar)

scheme@(guile-user)> (hello)
;;; <stdin>:4:0: warning: possibly unbound variable `hello'
<unnamed port>:4:0: In procedure #<procedure e3f580 at <current input>:4:0 ()>:
<unnamed port>:4:0: In procedure module-lookup: Unbound variable: hello

Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
scheme@(guile-user) [1]>

The question is: Is there a way to recover from this mistake in my live
REPL session?