[armedbear] #460: upgraded-array-element-type/class-of for arrays

[armedbear]

#460: upgraded-array-element-type/class-of for arrays
-------------------------+----------------------------
 Reporter:  mevenson     |           Owner:
     Type:  defect       |          Status:  new
 Priority:  major        |       Milestone:  1.5.1
Component:  interpreter  |         Version:  1.6.0-dev
 Keywords:               |  Parent Tickets:
-------------------------+----------------------------
 Alan notes in <https://github.com/armedbear/abcl/issues/84>
 {{{
 No code of mine depends on this, but I was reading an article and it
 prompted me to check types of arrays and how upgraded-array-element-type
 works.

 Bottom line is that it isn't consistent.

 CL-USER> (make-array 1 :element-type '(unsigned-byte 16))
 #(0)
 CL-USER> (jobject-class *)
 #<java class org.armedbear.lisp.BasicVector_UnsignedByte16 {6F28B4E2}>
 CL-USER> (class-of (make-array 1 :element-type '(unsigned-byte 16)))
 #<built-in-class vector {352D86C9}>
 CL-USER> (upgraded-array-element-type '(unsigned-byte 16))
 (unsigned-byte 16)
 CL-USER> (make-array 1 :element-type '(unsigned-byte 17))
 #(0)
 CL-USER> (jobject-class *)
 #<java class org.armedbear.lisp.BasicVector_UnsignedByte32 {1C49E33C}>
 CL-USER> (upgraded-array-element-type '(unsigned-byte 17))
 t
 CL-USER> (class-of (make-array 1 :element-type '(unsigned-byte 17)))
 #<built-in-class vector {352D86C9}>

 Summary:

     Implementation of arrays of unsigned byte 16 vs 17 are different
     class-of reports the same type
     upgraded-array-element-type of (unsigned-byte 17) reports t, but it is
 in fact (unsigned-byte 32)
     trying to set array element of (unsigned-byte 17) to int larger than
 2^17 works, but not setting to a symbol, as type t would imply
 }}}

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Ticket URL: <http://abcl.org/trac/ticket/460>
armedbear <http://abcl.org>
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