在 Perl 6 中用另一个数组的元素过滤一个数组的元素 [英] Filtering elements of an array with elements of another array in Perl 6

问题描述

我想过滤以 @search 元素开头的 @array 元素:

I want to filter elements of @array which begin with elements of @search:

my @array = "aaaaa" .. "fffff";
my @search = "aaaa" .. "cccc";
.put for @array .grep: /^ @search /;

问题是需要 19 秒.所以，我'预编译'grep 的regex，和整个程序如下所示:

The problem is it takes 19 seconds. So, I 'precompile' the regex for grep, and the whole program looks like this:

my @array = "aaaaa" .. "fffff";
my @search = "aaaa" .. "cccc";

my $search = "/@search.join('|')/".EVAL;

.put for @array .grep: * ~~ /^ <$search> /;

现在需要 0.444 秒.

Now it takes 0.444s.

问题:是否有内置的 Perl 6 方法来做这样的事情?类似于将 junction 插入 regex...

The question: is there a built-in Perl 6 method to do such things? Something like inserting a junction into a regex...

推荐答案

my @array = "aaaaa" .. "fffff";
my @search = "aaaa" .. "cccc";
my $join = @search.join('|');
my $rx = rx{ ^ <{$join}> };

@array.grep( * ~~ $rx ).map( *.put )

您需要单独创建连接字符串，它将为每个匹配评估数组连接.但是基本上不用EVAL就可以给你你想要的东西.

You need to create the join string separately of it will evaluate the array join for each match. But the basically gives you what you want without using EVAL.

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