mirror of
https://github.com/erg-lang/erg.git
synced 2025-08-04 02:39:20 +00:00
54 lines
1.3 KiB
Python
54 lines
1.3 KiB
Python
Empty = Class()
|
|
empty = Empty.new()
|
|
print! empty
|
|
|
|
# Inheritance is prohibited by default. Remove this decorator and check for errors.
|
|
@Inheritable
|
|
Point2D = Class {::[<: Self]x = Int; ::[<: Self]y = Int}
|
|
Point2D::
|
|
one = 1
|
|
Point2D.
|
|
zero = Point2D::one - 1
|
|
'''erg
|
|
p = Point2D.new {x = 1; y = 2}
|
|
assert p.norm() == 5
|
|
'''
|
|
norm self = self::x**2 + self::y**2
|
|
|
|
Point3D = Inherit Point2D, Additional := {z = Int}
|
|
Point3D.
|
|
# Overloading is prohibited by default. Remove this decorator and check for errors.
|
|
@Override
|
|
new x, y, z =
|
|
Point3D {x; y; z}
|
|
@Override
|
|
norm self = self::x**2 + self::y**2 + self::z**2
|
|
|
|
# `Point2D::__new__` is private, use `Point2D.new` instead
|
|
p = Point2D.new {x = 1; y = 2}
|
|
print! p, p.norm()
|
|
print! Point2D.zero
|
|
# print! Point2D::one # cannot access private variables
|
|
q = Point3D.new 1, 2, 3
|
|
print! q, q.norm()
|
|
|
|
# Newtype notation
|
|
# Shorthand of `IorS = Class {base = Int or Str}`
|
|
IorS = Class(Int or Str)
|
|
IorS.
|
|
is_int self =
|
|
# self: IorS
|
|
# self::base: Int or Str
|
|
match self::base:
|
|
(_: Int) -> True
|
|
_ -> False
|
|
is_str self =
|
|
match self::base:
|
|
(_: Str) -> True
|
|
_ -> False
|
|
|
|
# `.new` is of type `Int or Str -> IorS`, not `{base = Int or Str} -> IorS`
|
|
x = IorS.new 1
|
|
print! x
|
|
assert x.is_int()
|
|
assert not x.is_str()
|