[Sbcl-devel] Re: Type of MAKE-SEQUENCE

[Paul F. D. <di...@dl...>]

I wrote:
> I noticed that the compiler is not infering the type returned by 
> MAKE-SEQUENCE as well as it could:

The same thing happens with CONCATENATE:

* (let ((x (concatenate 'vector '(a a a a a a a a a a)))) (setf (aref x 4) 'b) x)
; in: LAMBDA NIL
;     (SETF (AREF X 4) 'B)
; --> SB-KERNEL:%ASET LET*
; ==>
;   (SB-KERNEL:HAIRY-DATA-VECTOR-SET ARRAY SB-INT:INDEX SB-C::NEW-VALUE)
;
; note: unable to
;         avoid runtime dispatch on array element type
;       because:
;         Upgraded element type of array is not known at compile time.
; compilation unit finished
;   printed 1 note

#(A A A A B A A A A A)
* (let ((x (the (vector t) (concatenate 'vector '(a a a a a a a a a a)))))
      (setf (aref x 4) 'b) x)

#(A A A A B A A A A A)
*

	Paul