Question

我认为问题标题有点令人困惑，但我无法找到更准确的方式来说明这一点。
我只需要一个简单的代码示例来告诉你我想要什么。

我有：

// code 1
interface A { A bla(); }
class B implements A { @Override public B bla() { return this; } }
class C implements A { @Override public C bla() { return this; } }

但实际上，这段代码也会编译（diff：查看返回类型声明）：

// code 2
interface A { A bla(); }
class B implements A { @Override public A bla() { return this; } }
class C implements A { @Override public A bla() { return this; } }

我希望代码2是类型错误说，我想强制每个A的子类＆＃39; bla方法返回自己，而不是A。

我认为可能有一个假代码来代表我想要的东西：

interface A { this.Type bla(); }

就像Haskell的类型类：

class Monad (m :: * -> *) where
  -- here m is restricted to the subclass
  (>>=) :: m a -> (a -> m b) -> m b

这可能吗？

Answer 1

不可能，但你可以这样做

import sys
import cx_Freeze
import os.path
import scipy

base = None

if sys.platform == 'win32':
    base = "Win32GUI"

#This part may depend on where your installation is
#This part is essential to copy the tkinter DLL files over
PYTHON_INSTALL_DIR = os.path.dirname(os.path.dirname(os.__file__))
os.environ['TCL_LIBRARY'] = os.path.join(PYTHON_INSTALL_DIR, 'tcl', 'tcl8.6')
os.environ['TK_LIBRARY'] = os.path.join(PYTHON_INSTALL_DIR, 'tcl', 'tk8.6')
os.environ['REQUESTS_CA_BUNDLE'] = r'C:\ProgramData\Anaconda3\Lib\site-packages\botocore\vendored\requests\cacert.pem'


executables = [cx_Freeze.Executable("test.py", base=base)]
addtional_mods = ['numpy.core._methods', 'numpy.lib.format']

packages = ["idna", "numpy", "boto3", 'boto3.s3.transfer', 'boto3.s3.inject', 'multiprocessing', "xlwt", 'numpy.core._methods', 'pandas']
options = {
    'build_exe': {

        'include_files':[
            os.path.join(PYTHON_INSTALL_DIR, 'DLLs', 'tk86t.dll'),
            os.path.join(PYTHON_INSTALL_DIR, 'DLLs', 'tcl86t.dll'),
            os.path.dirname(scipy.__file__),
            r'C:\ProgramData\Anaconda3\Lib\site-packages\botocore\vendored\requests\cacert.pem',
            r'C:\ProgramData\Anaconda3\Lib\site-packages\botocore',

         ],
        'includes': addtional_mods,
        'packages':packages,
    },

}

cx_Freeze.setup(
    name = "Test",
    options = options,
    version = "1.0.0.0",
    description = 'Test',
    executables = executables
)

我们能代表＆＃34;自我上课＆＃34;在Java（或Kotlin）？

1 个答案: