[armedbear-devel] [PATCH] Loading Lisp from JAR Files

[Mark Evenson]

Attached is a patch that allows LOAD to work on arbitrary JAR files.  It 
uses the semi-official ([according to Wikipedia][1] and as implemented 
in java.net.URL) URI Schema:

	jar:file:PATH!/JAR_ENTRY

where "file:PATH" is a filepath URI (meaning that absolute pathnames 
need to have a double leading slash, i.e. '//var/tmp/foo.jar'), and 
JAR_ENTRY is the path in the jar file.

I never could get Eric Marsden's patch to work, as it would load the 
initial FASL entry (the one ending in '._' containing the load 
instructions), but not the compiled classes.  It bothers me a little 
that following his instructions

Next steps:

1)  making this work for JARs containing "foo.abcl" zipped FASLs which 
are themselves zipped collections of a single FASL (ABCL overloads the 
".abcl" suffix to mean either a initial FASL OR a zipped collection of 
the initial FASL plus associated compiled toplevel forms).  Such zipped 
FASLs would be the natural unit for dealing with ABCL compile artifacts, 
right?

2)  Developing packaging utilities for putting together compilation 
units.  This would probably not be so necessary if step 1) can be made 
to work, right?

3) Check how this works under Microsoft Windows.


Question:

A)  There probably should be some way to load all the FASLs contained in 
a JAR.  Would

	(load "jar:file:foo.jar")

work as a syntax with the semantics of loading all the compiled classes 
that one can find in the associated JAR?

B)  I have deviated a little from Eric's original idea to bundle 
additional classes with the current abcl.jar for distribution, into 
having additional JARs with the extra classes.  If anything on the path 
that I am going does not meet up with use case expectations, please let 
me know.

Bugs:

I)  Currently the code has a bug that if a file whose name is a 
duplicate of one in the initial abcl.jar, it will not be loaded.


[1]: 
http://en.wikipedia.org/wiki/URI_scheme#Unofficial_but_common_URI_schemes

-- 
"A screaming comes across the sky.  It has happened before, but there
is nothing to compare to it now."
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