Well_ordered

Well-ordered is an ability of class.

let a = 1   // Int class has Well-ordered ability
let b = 10
puts a > b // false
puts a < b // true

let arr = [1, 3, 2]
puts a.sort()  // [1, 2, 3]

for i in a..b {
  puts i   // 1 2 3 ... 9
}

Requirement

Must implement following methods.

op_cmp(r):Int

Returns negative integer if left object is less than right. Returns positive integer if left object is greater than right. Otherwise returns 0

puts 1.op_cmp(3)  // -1
puts 1 < 3        // same as 1.op_cmp(3) < 0
puts 1 >= 3       // same as 1.op_cmp(3) >= 0