Re: [Scheme-reports] some questions on byte vectors + ports
Alex Shinn 27 Jun 2012 22:05 UTC
On Wed, Jun 27, 2012 at 2:56 PM, Aubrey Jaffer <agj@alum.mit.edu> wrote:
> | Date: Wed, 27 Jun 2012 14:14:02 -0700
> | From: Alex Shinn <alexshinn@gmail.com>
> |
> | On Wed, Jun 27, 2012 at 2:10 PM, Aubrey Jaffer <agj@alum.mit.edu> wrote:
> | > | Date: Wed, 27 Jun 2012 10:04:21 -0700
> | > | From: Alex Shinn <alexshinn@gmail.com>
> | > |
> | > | On Wed, Jun 27, 2012 at 9:52 AM, Aubrey Jaffer <agj@alum.mit.edu> wrote:
> | > | > ...
> | > | > SLIB provides R4RS/R5RS Scheme code to accomplish these conversions in
> | > | > a way which is unaffected by host byte-order. See:
> | > | > <http://people.csail.mit.edu/jaffer/slib/Byte_002fNumber-Conversions.html#Byte_002fNumber-Conversions>
> | > |
> | > | Note this is not truly portable in R4/R5 - you do need read-u8
> | > | and write-u8 provided by R6/R7.
> | >
> | > The SLIB conversions between numbers and byte-vectors do not require
> | > read-u8 or write-u8.
> |
> | Oh, I thought you were referring to the I/O operators. In that
> | case, it's still not portable R4/R5 because these had no portable
> | byte-vectors (without srfi-4 or one of the many array srfi's).
>
> The SLIB default implementation of byte-vectors is as arrays of bytes.
> The SLIB default implementation of arrays is portable R4RS/R5RS code
> which is included as the example implementation of SRFI-63,
> <http://srfi.schemers.org/srfi-63/srfi-63.html>.
>
> The SRFI-63 example code uses records (procedure calls; no macros);
> SLIB has a R4RS/R5RS compliant implementation of records at
> <http://savannah.gnu.org/cgi-bin/viewcvs/slib/slib/record.scm?rev=HEAD&content-type=text/vnd.viewcvs-markup>
>
> So you see Mr. Shinn, it's R4RS/R5RS-compliance all the way down.
Not down to the disk - everything is in in-memory Scheme
data structures and not at all addressing Wolfang's
needs, which is reading and writing these bytes from
files.
--
Alex
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