Erlang 中的元组模块是什么? [英] What is a tuple module in Erlang?

问题描述

http://www.erlang.org/news/35 提到这将被记录在案，但我可以在文档中找不到它.

http://www.erlang.org/news/35 mentioned that this will be documented, but I can't find it in the documentation.

推荐答案

元组模块"是具有两个元素的元组，模块名称和额外参数列表.例如:

A "tuple module" is a tuple with two elements, the name of a module and a list of extra arguments. For example:

{my_module, [foo, bar]}

在函数调用中可以使用这样的元组代替模块名称.在这种情况下，被调用的函数将获取有问题的元组作为参数列表末尾的附加参数:

Such a tuple can be used instead of a module name in function calls. In this case, the function being called will get the tuple in question as an additional argument at the end of the argument list:

3> Module = {lists, [[foo]]}.
{lists,[[foo]]}
4> Module:append([bar]).
[bar|{lists,[[foo]]}]

这个调用相当于:

7> lists:append([bar], {lists, [[foo]]}).
[bar|{lists,[[foo]]}]

保留元组模块是为了向后兼容，因为它们是参数化模块的实现机制, 已从 R16 中的语言中删除.

Tuple modules are kept for backwards compatibility, as they were the implementation mechanism for parameterised modules, which were removed from the language in R16.

这篇关于Erlang 中的元组模块是什么?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！