飞镖上是否有相当于python的dir()?

时间:2013-02-17 08:15:12

标签: dart dart-mirrors

正如标题所说,在飞镖上是否有相当于python的dir()

1 个答案:

答案 0 :(得分:9)

Python dir() function用于找出模块定义的名称。

我们可以使用Mirrors并自己编写一个等效函数(或者至少非常相似):

import 'dart:mirrors';

List<String> dir([String libraryName]) {
  var lib, symbols = [];

  if (?libraryName) {
    lib = currentMirrorSystem().libraries[libraryName];
  } else {
    lib = currentMirrorSystem().isolate.rootLibrary;
  }

  lib.members.forEach((name, mirror) => symbols.add(name));

  return symbols;
}

现在这是一个例子:

class Hello {}

bar() => print('yay');

main() {
  var foo = 5;

  print(dir()); // [main, bar, Hello, dir]
}

或指定一个库:

print(dir('dart:mirrors'));
  

[MirroredError,TypeMirror,ObjectMirror,_LazyLibraryMirror,   TypeVariableMirror,MirrorException,ClassMirror,MirrorSystem,   _LocalMirrorSystemImpl,_LocalVMObjectMirrorImpl,DeclarationMirror,_LazyTypeMirror,_LocalClosureMirrorImpl,mirrorSystemOf,_LazyFunctionTypeMirror,_filterMap,MirroredCompilationError,_Mirrors,_LocalClassMirrorImpl,_LocalInstanceMirrorImpl,_LocalTypedefMirrorImpl,   _LocalFunctionTypeMirrorImpl,reflect,MethodMirror,_LocalVariableMirrorImpl,LibraryMirror,_LocalIsolateMirrorImpl,FunctionTypeMirror,_LocalLibraryMirrorImpl,Mirror,   _LocalObjectMirrorImpl,_LocalMirrorImpl,_ makeSignatureString,_LocalTypeVariableMirrorImpl,Comment,MirroredUncaughtExceptionError,_LocalParameterMirrorImpl,_LazyTypeVariableMirror,TypedefMirror,VariableMirror,IsolateMirror,currentMirrorSystem,_dartEscape,   _LocalMethodMirrorImpl,ClosureMirror,VMReference,ParameterMirror,InstanceMirror,_isSimpleValue,SourceLocation]

这从字面上说明了在特定库(模块)中定义的内容。现在,Python的功能可能存在一些差异,这似乎也可以对名称进行排序,但这应该会给你一个良好的开端。

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