semicolon.cr

# OK
class A
  def a=(a)
    @a = a 
  end
end

# OK
class B
  def a=(a);@a = a;end
end

# NG
class C
  def a
    @a
  end

  def a=(a);@a = a end
end

# compile error
# class D
#   def a=(a);@a = a end
# end

[A, B, C].each do |klass|
  a = klass.new
  a.a = 2
  p a
end

# $ crystal --version
# Crystal 0.7.3 [bf72b07] (Sun Jun  7 16:17:59 UTC 2015)
# $ crystal semicolon.cr
# #<A:0x10f074ea0 @a=2>
# #<B:0x10f074e80 @a=2>
# #<C:0x10f078fe0 @a=nil>