From: Sonny To <son.c.to@gmail.com>
To: Per Bothner <per@bothner.com>
Cc: Kawa mailing list <kawa@sourceware.org>
Subject: Re: using lambda to implement one method interface
Date: Mon, 18 Sep 2017 08:17:00 -0000 [thread overview]
Message-ID: <CAJxjsJsz_NSmCgiX-PFRLFobZ39eW3H_yLWUo9Kp9QbPDC8_Fg@mail.gmail.com> (raw)
In-Reply-To: <CAJxjsJvfMzmMD654Jbxss0eKaFPfOvwgkH8seEwYq3t4846zzA@mail.gmail.com>
It seems implementing single method interface using lambda only works
with methods and not in constructors?
for example, this fails
#|kawa:137|# (java.lang.Thread (lambda ()
(+ 1 1)))
#|.....138|# /dev/stdin:137:1: warning - no possibly applicable method
'<init>/valueOf' in java.lang.Thread
gnu.mapping.WrongArguments
at gnu.mapping.MethodProc.matchFailAsException(MethodProc.java:136)
at gnu.kawa.reflect.Invoke.applyToObject(Invoke.java:264)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at gnu.mapping.CallContext$ReflectMethodHandle.invokeExact(CallContext.java:726)
at gnu.mapping.Procedure.applyToConsumerDefault(Procedure.java:75)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at gnu.mapping.CallContext$ReflectMethodHandle.invokeExact(CallContext.java:726)
at gnu.mapping.CallContext.runUntilDone(CallContext.java:586)
at gnu.expr.ModuleExp.evalModule2(ModuleExp.java:342)
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.repl.processArgs(repl.java:714)
at kawa.repl.main(repl.java:820)
On Mon, Sep 18, 2017 at 9:35 AM, Sonny To <son.c.to@gmail.com> wrote:
> yes that was an error. copy and paste of testing code. how would I
> implement an interface with multiple methods?
>
>
> On Sun, Sep 17, 2017 at 11:02 PM Per Bothner <per@bothner.com> wrote:
>>
>> On 09/17/2017 11:54 AM, Sonny To wrote:
>> > this is a big problem for my use case...
>> >
>> > i wouldn't be able to do something like this on android at runtime
>> >
>> > (object (java.lang.Runnable)
>> > ((run (a ::void))::void
>> > (+ 1 1)
>> > ))
>>
>> You can probably work around it with:
>>
>> (->java.lang.Runnable
>> (lambda ()::void (set! i (+ i 1))))
>>
>> BTW - I assume (a ::void) is just a typo. Kawa should probably complain
>> about it.
>> --
>> --Per Bothner
>> per@bothner.com http://per.bothner.com/
next prev parent reply other threads:[~2017-09-18 8:17 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-17 15:32 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 [this message]
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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