[Jscheme-user] Re: loading additional code in servlet?

[Timothy J. H. <ti...@cs...>]

On Aug 10, 2004, at 3:14 PM, Ken Anderson wrote:

> Tim,
> Your documentation mentions that a init.scm file is loaded the first 
> time a .servlet is executed.
>  How should a servlet that needs to load code do it so it only happens 
> once?
One way is to use the (use-module "FILE.scm") command
but we need to make a (reload-module "FILE.scm") command that can be 
used in development....

>
> Also, since all servlets run in the same environment, won't your 
> students potentially have name conflicts, at least potentially?
This is true, but I view it as a feature and not a bug.

The idea is to have the student's append their initials or login id to 
all their globally defined names
(e.g.   (define (tjh-webpage TITLE CSS BODY) ......)    )
then the students can load each others code and use each other's 
procedures ...

We could also have students use the
       (use-module "FILE.scm" 'import 'all "PREFIX:")
or (reload-module "FILE.scm" 'import 'all "PREFIX:")
approach to load in their code with a prefix..... This keeps the 
FILE.scm code simple
and still allows the libraries to be used without much interference...

This can be used to encourage a community of reuse. Student's in the 
summer course
thought it was very cool that they could all use everyone else 
procedures ....

I do need a way for them to reset the primitives, because last summer 
someone
wrote a servlet that started with
     (set! define 5)
which wiped out the real defintion of define!!

Another possibility would be to create a global hashtable H of 
jscheme.JScheme instances
and have a  macro that looked up the SchemeEvaluator in which to 
evaluate the servlet...

For example,

(use-context
    "tjh"

   (use-module "mydefs.scm" 'import 'all)
   ...
   (servlet  (a b c)
      BODY
    )
)

would lookup the context (a jscheme.JScheme. instance)
with key "tjh" (or create one if it doesn't exist), and then
evaluate the servlet in that context. Does this seem like
a reasonable approach??

---Tim---






>
> k
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