nim-codex/codex/units.nim

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## Nim-Codex
## Copyright (c) 2023 Status Research & Development GmbH
## Licensed under either of
## * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
## * MIT license ([LICENSE-MIT](LICENSE-MIT))
## at your option.
## This file may not be copied, modified, or distributed except according to
## those terms.
##
import std/hashes
import std/strutils
import pkg/upraises
import pkg/json_serialization
import pkg/json_serialization/std/options
type
NBytes* = distinct Natural
template basicMaths(T: untyped) =
proc `+` *(x: T, y: static[int]): T = T(`+`(x.Natural, y.Natural))
proc `-` *(x: T, y: static[int]): T = T(`-`(x.Natural, y.Natural))
proc `*` *(x: T, y: static[int]): T = T(`*`(x.Natural, y.Natural))
proc `+` *(x, y: T): T = T(`+`(x.Natural, y.Natural))
proc `-` *(x, y: T): T = T(`-`(x.Natural, y.Natural))
proc `*` *(x, y: T): T = T(`*`(x.Natural, y.Natural))
proc `<` *(x, y: T): bool {.borrow.}
proc `<=` *(x, y: T): bool {.borrow.}
proc `==` *(x, y: T): bool {.borrow.}
proc `+=` *(x: var T, y: T) {.borrow.}
proc `-=` *(x: var T, y: T) {.borrow.}
proc `hash` *(x: T): Hash {.borrow.}
template divMaths(T: untyped) =
proc `mod` *(x, y: T): T = T(`mod`(x.Natural, y.Natural))
proc `div` *(x, y: T): Natural = `div`(x.Natural, y.Natural)
# proc `/` *(x, y: T): Natural = `/`(x.Natural, y.Natural)
basicMaths(NBytes)
divMaths(NBytes)
proc `$`*(ts: NBytes): string = $(int(ts)) & "'NByte"
proc `'nb`*(n: string): NBytes = parseInt(n).NBytes
const
MiB = 1024.NBytes * 1024.NBytes # ByteSz, 1 mebibyte = 1,048,576 ByteSz
proc MiBs*(v: Natural): NBytes = v.NBytes * MiB
func divUp*[T: NBytes](a, b : T): int =
## Division with result rounded up (rather than truncated as in 'div')
assert(b != T(0))
if a==T(0): int(0) else: int( ((a - T(1)) div b) + 1 )
proc writeValue*(
writer: var JsonWriter,
value: NBytes
) {.upraises:[IOError].} =
writer.writeValue value.int
proc readValue*(
reader: var JsonReader,
value: var NBytes
) {.upraises: [SerializationError, IOError].} =
value = NBytes reader.readValue(int)
when isMainModule:
import unittest2
suite "maths":
test "basics":
let x = 5.NBytes
let y = 10.NBytes
check x + y == 15.NBytes
expect RangeDefect:
check x - y == 10.NBytes
check y - x == 5.NBytes
check x * y == 50.NBytes
check y div x == 2
check y > x == true
check y <= x == false