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Re: Module Import Bindings for Non-Main Classes
On 10/26/2011 12:22 PM, Taylor Venable wrote:
Thanks, I was reading that page but not looking in the right place. It
also says: "If 'init-run is specified, in addition the module body is
evaluated in the class's static initializer. (Otherwise, it is run the
first time it is require'd.)" That makes me think that the following
modification alone should work (that is, without using the init-run in
alpha.scm), but it does not:
(module-name "com.example.Beta")
(require com.example.Alpha)
(define (test)
(display test-a) (newline)
(display test-b) (newline)
(display test-c) (newline))
require and import are equivalent - both cause the imported module's
initializer (including the body) to be run.
The problem is gamma. It does not use either import or require,
so it just runs the Beta:test method *without insuring that Beta
has been initialized* - which means that Alpha hasn't been initialized
either.
What it says in the doc sounds good to me: if you require the module,
the module body will be evaluated, so that any fields within the module
are properly initialized for use that will come later. (Surely, if I
require it then I intend to use it in some way.) I would imagine that
would be good if it worked for the import syntax in addition to require.
It does, as far as I know.
I don't understand how the different behaviour between using Beta and
Gamma as the main class arises from this, however. Shouldn't the module
body of Alpha not be evaluated in both cases?
No - because the module body of Beta is not evaluated.
--
--Per Bothner
per@bothner.com http://per.bothner.com/