nimbus-eth1/src/utils_numeric.nim

import constants, strformat, macros

proc intToBigEndian*(value: Int256): cstring =
  result = cstring""

proc bigEndianToInt*(value: cstring): Int256 =
  result = 0.Int256

proc unsignedToSigned(value: Int256): Int256 =
  if value <= UINT_255_MAX:
    return value
  else:
    return value - UINT_256_CEILING

proc signedToUnsigned(value: Int256): Int256 =
  if value < 0:
    return value + UINT_256_CEILING
  else:
    return value

macro ceilXX(ceiling: static[int]): untyped =
  var name = ident(%"ceil{ceiling}")
  result = quote:
    proc `name`*(value: Int256): Int256 =
      var remainder = value mod `ceiling`.Int256
      if remainder == 0:
        return value
      else:
        return value + `ceiling`.Int256 - remainder
  echo result.repr

ceilXX(32)
ceilXX(8)