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* using lambda to implement one method interface
@ 2017-09-17 15:32 Sonny To
  2017-09-17 15:38 ` Sonny To
  0 siblings, 1 reply; 13+ messages in thread
From: Sonny To @ 2017-09-17 15:32 UTC (permalink / raw)
  To: Kawa mailing list

follwing docs at https://www.gnu.org/software/kawa/Anonymous-classes.html

(let ((handler (android.os.Handler (android.os.Looper:getMainLooper)))
      (runnable (lambda ()
                        (android.util.Log:i "scm" "run me"))))
  (handler:post runnable)
  )

that doesn't seem to work. Do I need to give type hints to be able to do this?

I'm getting this error:

#|.....44|# #|.....45|# #|.....46|# #|.....47|# /dev/stdin:46:17:
warning - type function is incompatible with required type
java.lang.Runnable
java.lang.ClassCastException: don't know how to coerce
gnu.expr.LambdaExp$Closure to java.lang.Runnable
        at gnu.bytecode.ObjectType.coerceFromObject(ObjectType.java:180)
        at gnu.kawa.functions.Convert.apply2(Convert.java:38)
        at gnu.mapping.Procedure2.applyToObject(Procedure2.java:62)
        at java.lang.reflect.Method.invoke(Native Method)
        at gnu.mapping.CallContext$ReflectMethodHandle.invokeExact(CallContext.java:726)
        at gnu.mapping.Procedure.applyToConsumerDefault(Procedure.java:75)
        at java.lang.reflect.Method.invoke(Native Method)
        at gnu.mapping.CallContext$ReflectMethodHandle.invokeExact(CallContext.java:726)
        at gnu.mapping.CallContext.runUntilDone(CallContext.java:586)
        at gnu.mapping.CallContext.getFromContext(CallContext.java:616)
        at gnu.expr.Expression.eval(Expression.java:52)
        at gnu.expr.ApplyExp.apply(ApplyExp.java:161)
        at gnu.expr.LetExp.apply(LetExp.java:72)
        at gnu.expr.ModuleExp.evalModule2(ModuleExp.java:281)
        at gnu.expr.ModuleExp.evalModule(ModuleExp.java:211)
        at kawa.Shell.run(Shell.java:283)
        at kawa.Shell.run(Shell.java:196)
        at kawa.Shell.run(Shell.java:183)
        at kawa.TelnetRepl.apply0(TelnetRepl.java:25)
        at gnu.mapping.RunnableClosure.run(RunnableClosure.java:75)
        at java.lang.Thread.run(Thread.java:764)

^ permalink raw reply	[flat|nested] 13+ messages in thread

end of thread, other threads:[~2017-09-18 14:31 UTC | newest]

Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-09-17 15:32 using lambda to implement one method interface Sonny To
2017-09-17 15:38 ` Sonny To
2017-09-17 15:59   ` Per Bothner
2017-09-17 16:04     ` Sonny To
2017-09-17 16:50       ` Per Bothner
2017-09-17 18:54         ` Sonny To
2017-09-17 20:02           ` Per Bothner
2017-09-18  6:35             ` Sonny To
2017-09-18  8:17               ` Sonny To
2017-09-18 13:59                 ` Per Bothner
2017-09-18 11:22               ` Sudarshan S Chawathe
2017-09-18 14:24                 ` Per Bothner
2017-09-18 14:31                   ` Sudarshan S Chawathe

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