[armedbear-devel] JSS issues: bug in jss::with-constant-signature, jss::invoke-find-method?

[Mark Evenson]

On 3/31/12 12:14 AM, Jonathan P. Bona wrote:
> Alan pointed out a JSS issue with passing of immediate values that may
> be related to the bug (report just sent) causing
> (jss::invoke-find-method "substring" "this is a string" '(1))  to
> return #<method public java.lang.String
> java.lang.String.substring(int,int)>
>
> Here are some of Alan's comments on this:
>
> Previously, in the old version of JSS:
> (new 'Boolean t) ->  #<java.lang.Boolean true {19FD541}>
>
> Now:
> (new 'Boolean t) ->  #<THREAD "interpreter" {4C4A0D}>: Debugger invoked
> on condition of type JAVA-EXCEPTION
>    Java exception 'java.lang.NoSuchMethodException:
> Boolean(org.armedbear.lisp.Symbol)'.
> Restarts:
>    0: TOP-LEVEL Return to top level.
>
> Notice that it has not translated the "t" to true as it used to. If
> method lookup is also not doing this then it makes sense that the
> method isn't found.
> (#"booleanValue" +true+) ->  t
> (#"valueOf" 'Boolean +true+) ->  t
> (#"valueOf" 'Boolean t) ->  error
>
> So it is clear that t isn't being coerced to boolean, which is done in
> method invoke-restargs in the old invoke.lisp:
>
> (dolist (arg args)
> 			(setf (jarray-ref argv (incf (the fixnum i)))
> 			     (if (eq arg t) true (if (eq arg nil) false arg))))
>
>
> But I still don't understand why (#"valueOf" 'Boolean +true+)  works.
> Here's the declaration: public static java.lang.Boolean
> java.lang.Boolean.valueOf(boolean)
>
> Apparently the compiler will unbox the Boolean to boolean for a method
> call. It doesn't for a method lookup I think. So they must have code
> for checking for both Boolean and boolean in the method signature when
> looking up the method.
>
> Only theory I have is that lookup of static methods is different from
> lookup of instance methods.
>
>
> On Fri, Mar 30, 2012 at 5:36 PM, Jonathan P. Bona
> <jonathanbona at gmail.com>  wrote:
>> I'm working with Alan Ruttenberg to port LSW from the old version of
>> JSS to the JSS that is now part of abcl-contrib.
>>
>> We've run into the following bug when using with-constant-signature:
>>
>> ; these first two work fine:
>> (#"substring" "some string" 2 4)  ; "me"
>> (#"substring" "some string" 2)     ; "me string"
>>
>> ; and so does this
>> (with-constant-signature ((substring "substring")) (substring "some
>> string" 2 4))   ; "me"
>>
>> ; but this breaks:
>> (with-constant-signature ((substring "substring")) (substring "some string" 2))
>> ; Wrong number of arguments for public java.lang.String
>> java.lang.String.substring(int,int): expected 2, got 1
>> ;   [Condition of type PROGRAM-ERROR]
>>
>>
>> A problem seems to be in jss::invoke-find-method, which is finding the
>> two argument version of java.lang.String.substring no matter how many
>> arguments its given:
>>
>> (jss::invoke-find-method "substring" "this is a string" '(1))  ;
>> should return the java.lang.String.substring method with one int arg
>> ; #<method public java.lang.String java.lang.String.substring(int,int)>
>>
>> (jss::invoke-find-method "substring" "this is a string" '(1 2) )
>> ; #<method public java.lang.String java.lang.String.substring(int,int)>
>>
>> (jss::invoke-find-method "substring" "this is a string" '(1 2 3 4 5 6
>> 7 8) )  ; should be an error
>> ; #<method public java.lang.String java.lang.String.substring(int,int)>
>>
>>
>>
>>
>> - Jonathan Bona
>
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>
Filed as [ticket][#205].  As soon as I write some tests to convince 
myself of the right cases to implement we should have this working for 
you in a couple days.  It vaguely smells like a problem left over from 
the graft from the jscheme arity matcher with a CL:APPLY.

At a minimum we should at least throw a condition with some args to 
inspect as to why we failed to match the plausible candidates which 
passed case insensitive string matching on the function names.

[#205]: http://trac.common-lisp.net/armedbear/ticket/205

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