Re: scoping rules

[Sonny To <son dot c dot to at gmail dot com>]

ok let me see if i can reproduce this outside of android

On Sun, Sep 17, 2017 at 10:45 AM, Per Bothner <per@bothner.com> wrote:
> On 09/17/2017 09:51 AM, Sonny To wrote:
>>
>> sorry for the newb question but i find this behavior odd
>>
>> (let ((handler (android.os.Handler (android.os.Looper:getMainLooper)))
>>        (c context))
>>    (handler:post (lambda ()
>>                          (let ((t (android.widget.Toast:makeText (as
>> android.app.Application c) "foobar"  1000)))
>>                            (t:show))
>>                          )))
>>
>> To get this example to work I had to bind c context in the top level let
>> in the second let, I have to use c instead of context directly.
>> (android.widget.Toast:makeText (as android.app.Application context)
>> will complain
>>
>> /dev/stdin:45:93: unbound location: context
>>
>> it could not see the context binding.
>> Should it not look in the environment? context is definitely in the
>> environment because the c binding works
>
>
> That does sound like a bug.  Probably the interaction of dynamic
> (environment) name-lookup
> combined with the use of the anonymous class.
>
> If you can create a simple non-Android test-case I'll take a look.
>
> It is recommended to include the line:
>
>     (define-variable context)
>
> as that tells the compiler to look for 'context' in the dynamic environment,
> and avoids warnings when using --warn-undefined-variable.
> --
>         --Per Bothner
> per@bothner.com   http://per.bothner.com/