Ruby on Rails：依赖项和节点

Question

我有一个简单的问题需要解决。我有一些代码可以根据其他任务对任务进行分类。例如任务 A、B、C 和 D。但是，这些需要按依赖顺序排序。例如，任务 B 只能在任务 D 完成后才能完成。因此任务的顺序是：

• 一个
• D
• B
• C

我有一些 Python 代码，有没有办法让这些代码在 Rails 中工作（如正确的语法/方法）

class Node:
def __init__(self, name):
  self.name = name
  self.edges = []

def addEdge(self, node):
  self.edges.append(node)

Answer 1

require 'set'

class CircularDependenciesError < Exception
end

class Task
  attr_reader :name, :depends

  def initialize(task_name, dependencies=[])
    @name = task_name
    @depends = Set.new dependencies
  end

  def add_dependencies(*d)
    @depends.merge d 
  end

  def <=>(rhs)
    if depends.include?(rhs.name) and rhs.depends.include?(name) 
      raise CircularDependenciesError,
            "#{name} and #{rhs.name} depend on each other"
    elsif rhs.depends.include? name 
      -1
    elsif depends.include? rhs.name
      1
    else 
      0
    end
  end
end

tasks = [
  Task.new("A", ["B", "C"]),
  Task.new("B", ["C", "D"]),
]

t = Task.new("C")
t.add_dependencies("D", "E")
tasks << t

p tasks
p tasks.sort

--output:--
[#<Task:0x000001018c0530 @name="A", @depends=#<Set: {"B", "C"}>>,
 #<Task:0x000001018c0350 @name="B", @depends=#<Set: {"C", "D"}>>,
 #<Task:0x000001018c01c0 @name="C", @depends=#<Set: {"D", "E"}>>]

[#<Task:0x000001018c01c0 @name="C", @depends=#<Set: {"D", "E"}>>,
 #<Task:0x000001018c0350 @name="B", @depends=#<Set: {"C", "D"}>>,
 #<Task:0x000001018c0530 @name="A", @depends=#<Set: {"B", "C"}>>]