[Jscheme-devel] feature request: strict-import

[Kyle R. B. <kyl...@gm...>]

The current import function is lazy, which nice from an interactive point of
view.  From knowing that the code will execute point of view, it is less
desirable.  I'd like to propose an additional function: strict-import that
would error if the class being imported is not actually found at the time
the strict-import is processed.

I can think of a few ways that strict-import could behave:

  (strict-import class-name)

In addition to calling Import.addImport, this would also validate that the
class can actually be loaded, otherwise it would throw an exception (class
not found exception).

  (strict-import "class.or.package.name.*")

If the arg prefix (dropping the wildcard) is a package name, then this works
exactly as the existing import (no detectable errors).  if the arg prefix is
a class name, then all the static methods in the class are imported as
symbols in the current environment:

  (strict-import "java.lang.Math.*")

Would create a function 'random in the current environment.

  (strict-import "java.lang.Math.random")

In this case the form is requesting the importing of a single static method
from the Math class, it would create a function 'random in the current
environment.


I can work at creating an example implementation some night this week (I
don't expect it to be difficult) if it is warranted.

We're using JScheme in one of our production applications (for a DSL) and
we're looking to have it be as strict as possible so that we end up
deferring as few errors/issues to runtime as possible.  Detecting failed
class imports (when the class is not actually on the classpath) would help
towards this goal.


Also, I've noticed that the implementation uses Vector and Hashtable quite a
bit.  I realize that they were what was available when JScheme was created
and the newer (and generally considered better) ArrayList and HashMap were
not available until java 1.2.  Is there any reason at this point not to
switch the code to use the newer collections framework?  There may be a
performance difference since ArrayList and HashMap are not synchronized
themselves - and it looks like the code in JScheme is doing a lot of the
synchronization itself anyway.


Thanks,

Kyle