I thought of one more thing that had been bouncing around. Compiler support for speed optimization. Currently I use the with-constant-signature macro, which lets me express that within a certain block a specified method will always be called with the same signature. The implementation is to cache the method looked up by the first call, and call that method throughout the rest of the block. It's pretty helpful for bumming speed on tight looks, such as when iterating through a large array or list. By doing this you save the lookup against the cache (and it makes a difference in some code).
Ideally this would be expressed as a compiler directive like (declare (constant-signature #"foo")) , which, if speed optimization was high enough, would do as I say above. I suppose the same declaration/optimization could be used for Clos method calls.
Finally, I haven't looked recently looked at the syntax for defining java classes and methods in lisp. jinterface-implementation gets the job done (though i used to have to be careful about exceptions - don't know if I still need to). But one might think a syntax closer to clos would be more familiar.
-Alan
On Sat, Feb 16, 2013 at 7:53 PM, Alan Ruttenberg alanruttenberg@gmail.com wrote:
Hi Blake,
I'm the original author of JSS and I completely agree. Have a look at JSS and see how it feels. Aside from the syntax, note that imports are not necessary, ABCL has incorporated dynamic additions to the classpath, one cnanan refer to classes using symbols or strings that only need to match uniquely to the end of the fully qualified class name and there are extensions to asdf that let you have jar files specified as part of system definitions.
The only thing that has stumped me is how to dynamically add native libraries - it would be great if you or someone Else could figure out a way to let that happen. Also I think there's one remaining bug with method look up that we've reported that I don't think is addressed yet.
I suspect it's the case that modifying a ABCL to use symbols as the function names is feasible just by modifying the readtable so you might give that a try. In the end I decided that because of the case sensitivity and the overlap with existing function names it was clearer to have a distinct syntax.
Here's another item that I think would be a very nice addition towards the goal we both agree is worthwhile. I find myself regularly finding some code snippet or test program written in java that I want to use in abcl. Wouldn't it be sweet if there was a slime addition paste-as-jss that did the transforms necessary to translate from java syntax to jss in ABCL. This wouldn't have to be a full java parser - even support for a subset of statements and the ability to ignore much of the declaration nonsense that jss/abcl doesn't need, and the ability to leave alone what it doesn't know how to translate, would be a real help for lisp programmers who want to use java.
Best, Alan
On Saturday, February 16, 2013, Blake McBride wrote:
I'd like to add that there are many high quality and free lisp systems available. The thing that makes ABCL uniquely interesting is its close association to Java. It gives ABCL a much better ability to leverage off of the existing technology (libraries) built in Java. While focusing on ABCL's reliability and conformance to standards is very important, I wouldn't loose sight of where the attraction really is. If the main attraction to ABCL for lisp programmers is its tight integration to Java, than the degree of ABCL's appeal will be directly related to the ease and power of its integration to Java.
Just one opinion...
Blake McBride
On Sat, Feb 16, 2013 at 7:54 AM, Alessio Stalla alessiostalla@gmail.com wrote:
On Sat, Feb 16, 2013 at 2:32 PM, Blake McBride blake@arahant.com wrote:
I have an idea for a largely seamless integration method for ABCL with Java that involves changing the ABCL REPL. It would work as follows.
- From within Java or lisp, have the ability to register any number
of Java classes with ABCL.
- When executing lisp code of the form (fun args ...), try running
the code as regular lisp code as it does now, but if it fails to find the lisp function and has at least one argument then:
- Examine the arguments and, through reflection, try to find a Java
method (with the same name as the lisp function) in one of the registered Java classes that matches the number and types of arguments and execute that. So, it would auto translate (in effect):
(fun arg1 arg2 arg3 ...)into Java
arg1.fun(arg2, arg3, ...);
- There must be better auto-translation of lisp <-> java data types
to include arrays and lists in order for this to work. So, in other words, when executing a lisp function passing a lisp array as one of the arguments, the Java reflection query will see a Java array argument type. It will also be auto-converted when making the call.
- There must be some sort of cacheing mechanism to avoid redundant
Java reflection calls.
- This mechanism must take into account and correctly handle similar
Java method names with different number and types of arguments both within and across different classes. It must also handle the fact that methods may be declared in Java superclasses.
- This functionality can be enabled or disabled through some (Java
and/or lisp function). Off by default to avoid troubles.
Adding this functionality would make ABCL a plugin-and-go extension to Java. Any code could be written in Java or lisp immediately without complicated and cumbersome interface/translation code in most cases. There would be no huge initial hill to climb (to create all the interface code), and the usage would be natural and uncomplicated.
Thanks.
I never really used it, but it seems to me that you're mostly describing JSS. It is not so seamlessly integrated with the REPL, but it has reader macros that allow you to write (#"someMethod" this arg1 arg2 ...). ABCL (and thus JSS) knows how to find the best matching method based on argument types, taking subclassing into account.
Lisp lists are not automatically translated to Java lists because they are made of conses, but a cons does not necessarily translate to a list, it might represent an improper list, a tree, a graph... on the other hand, you can use Java lists natively as Lisp sequences in ABCL, so you might be better off using Java lists from the start, if you find yourself converting lists back and forth frequently.
Alessio