Re: Is this a bug in 'read-vector?

>>>>> "Jeffrey" == Jeffrey Cunningham <[email protected]> writes:

    Jeffrey> I have been trying to read large binary files of floating point data
    Jeffrey> using CMUCL (19c). I thought I would have to do it using some form of
    Jeffrey> FFI and went to comp.lang.lisp for help getting that working. I
    Jeffrey> succeeded. But Duane Rettig at Allegro suggested it would be easier to
    Jeffrey> use 'read-vector. So I tried that as follows:

    Jeffrey> (let ((vec (make-array 10 :element-type 'double-float)))
    Jeffrey>   (with-open-file (os "d10.bin")
    Jeffrey>     (read-vector vec os)
    Jeffrey>     (print vec)))

    Jeffrey> where "d10.bin" is a double-float binary file containing 10
    Jeffrey> elements. When I try to read the file it produces the following error:

    Jeffrey> Type-error in KERNEL::OBJECT-NOT-DOUBLE-FLOAT-ERROR-HANDLER:
    Jeffrey>    #\Null is not of type DOUBLE-FLOAT

[snip]

    Jeffrey> Is this really a bug? Or am I doing something else wrong?

Yes, this does appear to be a bug in the implementation of
read-vector.

You can, however, achieve what you want by opening the file with an
element-type of, say, (unsigned-byte 8), instead of the default
'character.

I'll have to read some more to understand how read-vector interacts
with the stream element type.  It seems, though, that the element-type
of the vector overrides the element-type of the stream, more or less.
Currently, a stream element type of character basically causes the
code to read in characters.

Ray