使用定义的规则创建缩减 coderef 的库

发布于 2024-11-24 08:22:02 字数 1041 浏览 1 评论 0原文

是否有现有的 CPAN 库能够从基本测试的结构化输入创建 coderef，将传递的数据结构简化为真/假值？它需要能够将构造函数传递的属性映射到传递的数据结构的属性（即，在下面的示例中 [attribute => 'something'] 映射到 $_-> ;{something} 在传递的标量上）并对它们执行测试。

我可以写一些东西，但我真的很惊讶我没有在 CPAN 上找到任何东西来处理它。有谁知道有图书馆可以做这种事情吗？

my @def = ( [ [ attribute => 'something' ], '>', 50 ],
            'and',
            [ [ attribute => 'something_else' ], 'eq', 'match' ],
          );

my $coderef = Reducer->new(@def);

my @items = ( { something => 75,
                something_else => 'match',
              },
              { something => 20,
                something_else => 'match',
              },
              { something => 75,
                something_else => 'no match',
              },
              { something => 90,
                something_else => 'match',
              },
            );

for my $item (@items) {
  $coderef->($item) ? say 'true' : say 'false';
};

输出：

true
false
false
true

原文

Is there an existing CPAN library that's able to create coderefs from a structured input of basic tests that reduce a passed data structure to a true/false value? it needs to be able to map passed attributes from the constructor onto the passed data structure's attributes (i.e., in the example below [attribute => 'something'] maps to $_->{something} on the passed scalar) and perform tests against them.

I could write something, but I'm really surprised I'm not finding anything on CPAN to handle it. Does anyone know of a library to do this sort of thing?

my @def = ( [ [ attribute => 'something' ], '>', 50 ],
            'and',
            [ [ attribute => 'something_else' ], 'eq', 'match' ],
          );

my $coderef = Reducer->new(@def);

my @items = ( { something => 75,
                something_else => 'match',
              },
              { something => 20,
                something_else => 'match',
              },
              { something => 75,
                something_else => 'no match',
              },
              { something => 90,
                something_else => 'match',
              },
            );

for my $item (@items) {
  $coderef->($item) ? say 'true' : say 'false';
};

outputs:

true
false
false
true

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霊感 2024-12-01 08:22:03

关于这个问题或者您的示例代码确实没有什么需要通过 coderef 来解决的；您更有可能找到一个将定义和要验证的项目作为参数的子例程。

我知道其中有几个；首先想到的是 Params::Validate::validate。

尽管定义结构与您的不同（验证规范的属性散列而不是数组等），但将您想要的接口包装起来是微不足道的。

package Params::Validate::Reducer;
use strict;
use warnings;
use Params::Validate ();
sub new {
    my ($class, $def) = @_;
    sub {
        !! eval {
            Params::Validate::validate(@_, $def);
            1;
        }
    }
}

Nothing about this problem or indeed your example code cries out to be solved by a coderef to me; you are more likely to find a subroutine that takes both the definition and item to validate as parameters.

I know there are several of those; the one that comes to mind first is Params::Validate::validate.

It would be trivial to wrap your desired interface around that, though the definition structure would differ from yours (a hash of attribute to validation spec instead of an array, etc).

package Params::Validate::Reducer;
use strict;
use warnings;
use Params::Validate ();
sub new {
    my ($class, $def) = @_;
    sub {
        !! eval {
            Params::Validate::validate(@_, $def);
            1;
        }
    }
}

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