peon/src/util/multibyte.nim

85 lines
2.5 KiB
Nim

# Copyright 2022 Mattia Giambirtone & All Contributors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
## Utilities to handle multibyte sequences
proc toDouble*(input: int | uint | uint16): array[2, uint8] =
## Converts an unsigned integer
## to an array[2, uint8]
result = cast[array[2, uint8]](uint16(input))
proc toTriple*(input: uint | int): array[3, uint8] =
## Converts an unsigned integer to an array[3, uint8]
result = cast[array[3, uint8]](uint(input))
proc toQuad*(input: int | uint | uint16 | uint32): array[4, uint8] =
## Converts an unsigned integer to an array[4, uint8]
result = cast[array[4, uint8]](uint(input))
proc toLong*(input: int | uint | uint16 | uint32 | uint64): array[8, uint8] =
## Converts an unsigned integer to an array[8, uint8]
result = cast[array[8, uint8]](uint(input))
proc fromDouble*(input: array[2, uint8]): uint16 =
## Rebuilds the output of toDouble into
## an uint16
copyMem(result.addr, unsafeAddr(input), sizeof(uint16))
proc fromTriple*(input: array[3, uint8]): uint =
## Rebuilds the output of toTriple into
## an uint
copyMem(result.addr, unsafeAddr(input), sizeof(uint8) * 3)
proc fromQuad*(input: array[4, uint8]): uint =
## Rebuilts the output of toQuad into
## an uint
copyMem(result.addr, unsafeAddr(input), sizeof(uint32))
proc fromLong*(input: array[8, uint8]): uint =
## Rebuilts the output of toQuad into
## an uint
copyMem(result.addr, unsafeAddr(input), sizeof(uint64))
proc toBytes*(s: string): seq[byte] =
## Converts a string into a sequence
## of bytes
for c in s:
result.add(byte(c))
proc toBytes*(s: int): array[8, uint8] =
## Converts
result = cast[array[8, uint8]](s)
proc fromBytes*(input: seq[byte]): string =
## Converts a sequence of bytes to
## a string
for b in input:
result.add(char(b))
proc extend*[T](s: var seq[T], a: openarray[T]) =
## Extends s with the elements of a
for e in a:
s.add(e)