bytevector-s16-set!, bytevector-s32-set!, bytevector-s64-set!, bytevector-u16-set!, bytevector-u32-set!, bytevector-u64-set!, bytevector-ieee-double-set!, bytevector-ieee-single-set!, bytevector-s16-native-set!, bytevector-s32-native-set!, bytevector-s64-native-set!, bytevector-u16-native-set!, bytevector-u32-native-set!, bytevector-u64-native-set!, bytevector-ieee-double-native-set!, bytevector-ieee-single-native-set! - store a number in a bytevector

---

LIBRARY

(import (rnrs))                     ;R6RS
(import (rnrs bytevectors))         ;R6RS

SYNOPSIS

(bytevector-s16-set! bytevector k n endianness)
(bytevector-s32-set! bytevector k n endianness)
(bytevector-s64-set! bytevector k n endianness)

(bytevector-u16-set! bytevector k n endianness)
(bytevector-u32-set! bytevector k n endianness)
(bytevector-u64-set! bytevector k n endianness)

(bytevector-ieee-double-set! bytevector k x endianness)
(bytevector-ieee-single-set! bytevector k x endianness)

(bytevector-s16-native-set! bytevector k n)
(bytevector-s32-native-set! bytevector k n)
(bytevector-s64-native-set! bytevector k n)

(bytevector-u16-native-set! bytevector k n)
(bytevector-u32-native-set! bytevector k n)
(bytevector-u64-native-set! bytevector k n)

(bytevector-ieee-double-native-set! bytevector k x)
(bytevector-ieee-single-native-set! bytevector k x)

DESCRIPTION

s16

signed 16-bit integer

s32

signed 32-bit integer

s64

signed 64-bit integer

u16

unsigned 16-bit integer

u32

unsigned 32-bit integer

u64

unsigned 64-bit integer

ieee-double

IEEE-754 double-precision float (binary64)

ieee-single

IEEE-754 single-precision float (binary32)

The signed variants use the two's complement representation.

The endianness is normally one of the following symbols:

big

Big endian. The more significant bytes come before the less significant bytes.

little

Little endian. The less significant bytes come before the more significant bytes.

The -native variants use the machine's native endianness and furthermore impose an alignment requirement: the index k must be evenly divisible by the data type size (2, 4 or 8). Such an access is said to be aligned, as opposed to an unaligned access.

The number of bytes m used depends on the data type and is either two, four or eight (corresponding to 16, 32 or 64 bits). The bytevector must be at least k+m bytes in length.

The integer n must be in the range [0, (2^w)-1] for the unsigned operations and in the range [-(2^(w-1)), (2^(w-1))-1] for the signed operations, where w is the size of the data type in bits. For the floating point operations, x must be a real number object.

Unlike the equivalent operation in e.g. C, the index is not multiplied by the element size.

RETURN VALUES

EXAMPLES

(define b
  (u8-list->bytevector
    '(255 255 255 255 255 255 255 255
      255 255 255 255 255 255 255 253)))

(bytevector-u16-set! b 0 12345 (endianness little))
(bytevector-u16-ref b 0 (endianness little))
          => 12345

(bytevector-u16-native-set! b 0 12345)
(bytevector-u16-native-ref b 0)
          => 12345
(bytevector-u16-ref b 0 (endianness little))
          => unspecified

COMPATIBILITY

ERRORS

&assertion (R6RS)

The wrong number of arguments was passed or an argument was outside its domain.

R7RS

The assertions described above are errors. Implementations may signal an error, extend the procedure's domain of definition to include such arguments, or fail catastrophically.

SEE ALSO

STANDARDS

AUTHORS

BUGS