多个 MAIN 签名 [英] Multiple MAIN signatures

问题描述

我有一个包含多个 main 的包，我想定义几个选项:

I have a package with multiple main and I want to define several options:

我的代码是这样的:

package Perl6::Documentable::CLI {
    proto MAIN(|) is export {*}
    my %*SUB-MAIN-OPTS = :named-everywhere;

    multi MAIN(
        "setup"
    ) { ... }

    multi MAIN (
        "start"                           ,
        Str  :$topdir              = "doc",
        Bool :v(:verbose($v))      = False
    ) { ... }

但是当我尝试实际执行它时:

But when I try to actually execute it with:

perl6 -Ilib bin/documentable start -v --topdir=ss

它输出这一行:

Usage:
  bin/documentable [--topdir=<Str>] [-v|--verbose] start

我正在使用 %*SUB-MAIN-OPTS 但它看起来也不起作用.

I am using %*SUB-MAIN-OPTS but it looks like it does not work neither.

推荐答案

最简单的解决方案是导出动态变量 %*SUB-MAIN-OPTS，但这仍然没有完全实现:导出工作正常，但最终成为一个空哈希.所以不是很有用.

The simplest solution would be to export the dynamic variable %*SUB-MAIN-OPTS, but that is still Not Yet Implemented completely: the export works sorta, but winds up being an empty hash. So not very useful.

Rakudo 会在决定要运行一个 MAIN 子程序时调用一个名为 RUN-MAIN 的子程序.你可以从你的模块中实际导出一个RUN-MAIN，并设置动态变量，然后调用原来的RUN-MAIN:

Rakudo will call a subroutine called RUN-MAIN when it decides there is a MAIN sub to be run. You can actually export a RUN-MAIN from your module, and set up the dynamic variable, and then call the original RUN-MAIN:

sub RUN-MAIN(|c) is export {
    my %*SUB-MAIN-OPTS = :named-anywhere;
    CORE::<&RUN-MAIN>(|c)
}

有关 RUN-MAIN 的更多信息，请参阅:https://docs.raku.org/language/create-cli#index-entry-RUN-MAIN

For more information about RUN-MAIN, see: https://docs.raku.org/language/create-cli#index-entry-RUN-MAIN

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