oop_utils

oop_utils provides macros that allow to easily create OOP class hierarchies.

It comes in two different flavors:

Standard classes: Allows to define type hierarchies based on Nim's standard method dispatch.
Closure classes: Allows to define type hierarchies based on closure method dispatch.

The two approaches have minor syntactical differences, but share the same general scheme. For comparison:

import oop_utils/standard_class

# A standard class:
# - The object instance is attached to a `self` symbol.
# - Initialization + field definitions go into the ctor proc.
class(Counter):
  ctor(newCounter) proc(init: int) =
    self:
      counter = init

  method inc*() {.base.} = self.counter.inc
  method dec*() {.base.} = self.counter.dec
  method get*(): int {.base.} = self.counter

vs.

import oop_utils/closure_class

# A closure class:
# - No `self` symbol required.
# - Initialization + field definitions go into main scopre to emphasize closure nature.
class(Counter):
  ctor(newCounter) proc(init: int)

  var counter = init

  proc inc*() = counter.inc
  proc dec*() = counter.dec
  proc get*(): int = counter