Compiler construction OCAML中的循环依赖控制

[编辑]

谢谢你的回答，我的问题如下：

称为Map.ml的模块A

let lst = ref [Instance1_ModuleB; Instance2_ModuleB; ...];;
let is_coliding p = DoSomeWork_And_Return_A_Bool ;;
.... other things here.

Open Map
class player_object (x_in, y_in, name_in)=

object (self)

method jump () =
       if Map.is_colliding self then
             DoSomeThing ();;
....

称为Player.ml的模块B

let lst = ref [Instance1_ModuleB; Instance2_ModuleB; ...];;
let is_coliding p = DoSomeWork_And_Return_A_Bool ;;
.... other things here.

Open Map
class player_object (x_in, y_in, name_in)=

object (self)

method jump () =
       if Map.is_colliding self then
             DoSomeThing ();;
....

任何关于如何让它起作用的线索

顺便问一下，其他编程语言是如何做到这一点的？我从来不在乎C语言中的这种依赖性

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谢谢

如果您的模块A只需要模块B中的类型而不需要值，那么您可以使用模块B的接口创建moduleB.mli，并在模块A之前编译它：

moduleA.ml：

let foo (bar : ModuleB.bar) = bar.baaz

let li = [new bar; new bar]

let foo (bar : ModuleB.bar) = bar.baaz

let li = [new bar; new bar]

let foo (bar : ModuleB.bar) = bar.baaz
let _ = ModuleB.initB foo

moduleB.mli：

class bar : object
  method baaz : int
  method buz : int
end

模B.ml

class bar =
object(s)
  method baaz = 3
  method buz = ModuleA.foo s
end

let foo = ref (fun x -> (failwith "not initialized" : int))

class bar =
object(s)
  method baaz = 3
  method buz = !foo s
end

let initB f = foo := f

但如果您对值或函数有循环依赖，则没有简单的解决方案，例如：

moduleA.ml：

let foo (bar : ModuleB.bar) = bar.baaz

let li = [new bar; new bar]

let foo (bar : ModuleB.bar) = bar.baaz

let li = [new bar; new bar]

let foo (bar : ModuleB.bar) = bar.baaz
let _ = ModuleB.initB foo

通常，可以尝试使用引用或可变值来打破这种循环依赖关系：

moduleA.ml：

let foo (bar : ModuleB.bar) = bar.baaz

let li = [new bar; new bar]

let foo (bar : ModuleB.bar) = bar.baaz

let li = [new bar; new bar]

let foo (bar : ModuleB.bar) = bar.baaz
let _ = ModuleB.initB foo

模B.ml

class bar =
object(s)
  method baaz = 3
  method buz = ModuleA.foo s
end

let foo = ref (fun x -> (failwith "not initialized" : int))

class bar =
object(s)
  method baaz = 3
  method buz = !foo s
end

let initB f = foo := f