Unbound scheme procedures when calling from Java

[Vladimir Tsichevski]

Esko Nuutila wrote:

>We are trying to call our own Scheme procedures from Java.  The
>problem is that only a part of the Scheme standard procedures seem to
>be bound.  When using kawa interactively these procedures have correct
>bindings.  The following files illustrate the problem:
>
>===small.scm===
>
>;;; Is reverse and append bound in the current environment?
>(define (test)
>  (format #t "Reverse = ~S~%" reverse)
>  (format #t "Append = ~S~%" append))
>
>===UseSmall.java===
>
>import kawa.standard.Scheme;
>
>public class UseSmall {
>    public static void main(String[] args) {
>	Scheme.registerEnvironment();
>	small.test();
>    }
>}
>
>===interactive run===
>
>  
>
>>kawa
>>    
>>
>#|kawa:1|# (load "small")
>#|kawa:2|# (test)
>Reverse = #<procedure reverse>
>Append = #<procedure append>
>#|kawa:3|#
>
>===Call from Java===
>
>  
>
>>java UseSmall
>>    
>>
>Reverse = #<procedure reverse>
>Exception in thread "main" java.lang.NullPointerException
>        at small.test(small.scm:4)
>        at UseSmall.main(UseSmall.java:6)
>
>====
>
>What can be the problem here? Is this the correct way to use Scheme
>from Java?
>
>Esko Nuutila
>

Hi,

I see small.test() in your code, so you implicitly suppose all methods 
in small.scm are static. This is probably
not the case. Use (module-static #t) to force compilation of all module 
procedures as static.

Here is what I got:

bash-2.05a$ cat small.scm
(module-static #t)
(define (test)
  (format #t "Reverse = ~S~%" reverse)
  (format #t "Append = ~S~%" append))
bash-2.05a$ cat UseSmall.java
import kawa.standard.Scheme;

public class UseSmall {
    public static void main(String[] args) {
    Scheme.registerEnvironment();
    small.test();
    }
}

bash-2.05a$ kawa -C small.scm
(compiling small.scm)
bash-2.05a$ javac UseSmall.java
bash-2.05a$ java UseSmall
Reverse = #<procedure reverse>
Append = #<procedure append>


Regards,

Vladimir