Module Netnumber

module Netnumber: sig .. end

Binary encodings of numbers

This is the successor of the Rtypes module

Numeric types

type int4

32 bit signed integer

type int8

64 bit signed integer

type uint4

32 bit unsigned integer

type uint8

64 bit unsigned integer

type fp4

single precision float (IEEE "float")

type fp8

double precision float (IEEE "double")

exception Cannot_represent of string

raised if a conversion can't be done

exception Out_of_range

raised if string position out of range

Basic encoding/decoding functions

val mk_int4 : char * char * char * char -> int4

val mk_int8 : char * char * char * char * char * char * char * char -> int8

val mk_uint4 : char * char * char * char -> uint4

val mk_uint8 : char * char * char * char * char * char * char * char -> uint8

mk_<t> create integer values from character tuples. In these tuples the MSB is the first component and the LSB the last.

val dest_int4 : int4 -> char * char * char * char

val dest_int8 : int8 -> char * char * char * char * char * char * char * char

val dest_uint4 : uint4 -> char * char * char * char

val dest_uint8 : uint8 -> char * char * char * char * char * char * char * char

dest_<t> destroy integer values and returns the corresponding char tuples.

val mk_fp4 : char * char * char * char -> fp4

val mk_fp8 : char * char * char * char * char * char * char * char -> fp8

val dest_fp4 : fp4 -> char * char * char * char

val dest_fp8 : fp8 -> char * char * char * char * char * char * char * char

Conversions

Conversions from int to (u)int and vice versa. On 32-bit computers, the type int can hold 31-bit signed integers (including the sign, i.e. one bit cannot be used). On 64-bit computers, the type int can hold 63-bit signed integers (including the sign, i.e. one bit cannot be used). The int_of_xxx functions raise Cannot_represent if the number to convert is too big (or too small) to be represented as int. Note that this depends on the word size of your architecture.

val int_of_int4 : int4 -> int

val int_of_uint4 : uint4 -> int

val int_of_int8 : int8 -> int

val int_of_uint8 : uint8 -> int

val int4_of_int : int -> int4

val uint4_of_int : int -> uint4

val int8_of_int : int -> int8

val uint8_of_int : int -> uint8

val int32_of_int4 : int4 -> int32

val int32_of_uint4 : uint4 -> int32

val int32_of_int8 : int8 -> int32

val int32_of_uint8 : uint8 -> int32

val int4_of_int32 : int32 -> int4

val uint4_of_int32 : int32 -> uint4

val int8_of_int32 : int32 -> int8

val uint8_of_int32 : int32 -> uint8

val int64_of_int4 : int4 -> int64

val int64_of_uint4 : uint4 -> int64

val int64_of_int8 : int8 -> int64

val int64_of_uint8 : uint8 -> int64

val int4_of_int64 : int64 -> int4

val uint4_of_int64 : int64 -> uint4

val int8_of_int64 : int64 -> int8

val uint8_of_int64 : int64 -> uint8

Casts from uint4/uint8 to int32/int64. Here, the sign is ignored and simply considered as a bit.

val logical_uint4_of_int32 : int32 -> uint4

val logical_int32_of_uint4 : uint4 -> int32

val logical_uint8_of_int64 : int64 -> uint8

val logical_int64_of_uint8 : uint8 -> int64

val fp8_of_fp4 : fp4 -> fp8

val fp4_of_fp8 : fp8 -> fp4

Note fp4_of_fp8: This conversion is not exact. It is quite normal that precision is lost. Numbers too small or too large for fp4 are converted to the "infinity" value.

val float_of_fp4 : fp4 -> float

val float_of_fp8 : fp8 -> float

val fp4_of_float : float -> fp4

val fp8_of_float : float -> fp8

Note fp4_of_float: The same problems as in fp4_of_fp8 may arise

Comparisons

The comparisons "=" and "<>" work for all numbers.

For signed integers, the operators "<", "<=", ">", and ">=" work, too. The unsigned integer type use representation that are not compatible with these operators, and the following functions need to be called.

For fp4 and fp8 there are no comparison functions - convert to float first and compare then.

val lt_uint4 : uint4 -> uint4 -> bool

lt_uint4 is true iff the first value is less than the second value as unsigned int

val le_uint4 : uint4 -> uint4 -> bool

val gt_uint4 : uint4 -> uint4 -> bool

val ge_uint4 : uint4 -> uint4 -> bool

Other comparisons

val lt_uint8 : uint8 -> uint8 -> bool

lt_uint8 is true iff the first value is less than the second value as unsigned int

val le_uint8 : uint8 -> uint8 -> bool

val gt_uint8 : uint8 -> uint8 -> bool

val ge_uint8 : uint8 -> uint8 -> bool

Other comparisons

module type ENCDEC = sig .. end

module BE: ENCDEC

Encoders/decoders for big endian - network byte order

module LE: ENCDEC

Encoders/decoders for little endian

module HO: ENCDEC

Encoders/decoders for host byte order - which is either little endian or big endian, depending on the CPU (or CPU mode)

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