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Signature PACK_REAL (basis)

Operations for packing and unpacking real values.

structure PackRealLittle : PACK_REAL (basis)
structure PackRealBig : PACK_REAL (basis)

signature PACK_REAL =
  sig
    type real
    val bytesPerElem : int
    val isBigEndian : bool
    val toBytes   : real -> Word8Vector.vector
    val fromBytes : Word8Vector.vector -> real
    val subVec : Word8Vector.vector * int -> real
    val subArr : Word8Array.array * int -> real
    val update : Word8Array.array * int * real -> unit
  end

[bytesPerElem]

The number of bytes per element, sufficient to store a value of type real.

[isBigEndian]

is true if the structure implements a big-endian view of the data.

[toBytes r]

[fromBytes v]

These functions pack and unpack floating-point values into and out of Word8Vector.vector values. The function fromBytes raises the Subscript exception if the argument vector does not have length at least bytesPerElem; otherwise the first bytesPerElem bytes are used.

[subVec (seq, i)]

[subArr (seq, i)]

These functions extract the subsequence

    seq[bytesPerElem*i..bytesPerElem*(i+1)-1]

of the aggregate seq and convert it into a real value according to the endianness of the structure. They raise the Subscript exception if i < 0 or if Word8Array.length seq < bytesPerElem * (i + 1).

[update (arr, i, r)]

stores r into the bytes bytesPerElem*i through bytesPerElem*(i+1)-1 of the array arr, according to the structure's endianness. It raises the Subscript exception if i < 0 or if Word8Array.length arr < bytesPerElem * (i + 1).