On 5/17/11 10:01 PM, Faré wrote:
I'm gonna need a bit more time to chew over the ASDF code, but thanks for the general direction. I must confess that in spite of the reasonable looking documentation and having contributed the function translation code to ASDF, its whole output translation API has never really gelled in my understanding as a totality. Maybe I can contribute some examples to the texinfo file when the fuzz in my understanding resolves a bit.
output-translations is not THAT hard to understand, if you read the source code with my previous comments in mind. Patches to the docs are welcome, too.
I agree it shouldn't be that hard. And every time I read the code and docs I go "Uh-huh, now I understand." But somehow, like Perl code, when I come back to it two weeks later, I have to start from the beginning. I guess I'm just putting the proverbial stake in the ether to mark my frustration in case others have the same problem, as a) I'm old enough not to care that much if other people think I'm an idiot and b) maybe it's not just me. In amplifying my concern here, I definitely owe you a diff or two to asdf.texinfo to reward your patient explanations…
[…]
- You can't immediately load FASL out of the jar.
Is that an ABCL limitation?
Certainly not: abcl.jar contains FASLs, after all.
In my current hackish way—i.e. without comprehending your advice yet—one has first ASDF compile the system with output translations disabled, and then
(defmethod asdf:perform ((o asdf:compile-op) (c asdf:cl-source-file))) (setf (asdf::output-translations) '((t t))))
in the target JVM to load the ABCL FASLS from the jar.
Why that pain? Doesn't the zip process preserve the timestamps?
Timestamps should be preserved, but the current output translation code looks for FASLs in the user cache. Well, by that reasoning including both statements should be redundant. I need to look at this again…
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You want CL systems to be in a variety of jars, rather than just a one jar with everything in it?
Yep. I wouldn't mind being able to include multiple systems in a single jar, but I want to keep the core abcl separate from the systems in order to be able to consistently rev the core (and, of course, the systems) via checksums.
- The extremely nice use of [JSS][jss] and [ABCLD's slight
modification][abcld] of ASDF to also refer to jar files to dynamically load into the JVM probably needs to be rewritten, otherwise we run into the situation whereby we have jars (i.e. the packaged Java code) within the ASDF packaged jar which A) needs changes within ABCL to completely work and B) would be rather inefficient in that the naive implementation each request for a new entry in the JAR within a JAR would require a complete "reseek" through the enclosed ZIP file.
I welcome patches to ASDF and/or implementation-specific contributions, just like our asdf-ecl.lisp.
I have my eye on that, and when I have mature patches to ASDF that work with ABCL out of the box, I will submit them for consideration. But currently, one needs a specialized build of ABCL with the jscheme and bsh jars in the classpath in order to use the jar-file extensions so this isn't practical. Given the amount of ABCL's lunch that Clojure has eaten, maybe it's time to make some post-ANSI CL decisions in our implementation wrt. ABCL Java/CL interop.
- A fear of mine: if I enable all this, I presume that people would start
going around creating 'abcl.jar' files with different inclusions of different ASDF packagings. Without a real smart dynamic introspection system that essentially solves the problems in JVM's classpath we would end up with, at the minimum, a rather hostile situation for the end user. "Put 'abcl.jar' in your classpath." "I did, and it still didn't load Maxima." "Well, what's the checksum of your abcl.jar?" "c48d359a23ee" "Oh, you need 846f78c279cb". Ideally, I would like to come up with a mechanism that would require that 'abcl.jar' come from "official" ABCL packaging, but would somehow be able to introspect the JVM classpath to include ASDF definitions.
Maybe make it hard for anything but the original to be named abcl.jar?
Not really possible as far as I can figure things to avoid the ability to name things 'abcl.jar' (or are you being sarcastic?) Solving the dynamic introspection problem seems more tractable, at the corresponding runtime cost of building a cache of the contents jars that the JVM knows about, but memory is getting cheaper by the ns, n'est-ce pas?