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librasteve's questions

Martin Hope
librasteve
Asked: 2023-12-02 19:50:44 +0800 CST
  • 9

我有这个 raku 语法：

#!/usr/bin/env raku
use v6.d;

use Grammar::Tracer;

grammar Grammar {
    token TOP {
          <city>      \v
          <state-zip> \v?
    }
    token city {
        ^^ \V* $$
    }
    token state-zip {
        ^^ <state> <.ws>? <zipcode> $$    #<.ws> is [\h* | \v]
    }
    token state {
        \w \w
    }
    token zipcode {
        \d ** 5
    }
}

class Actions {
    method TOP($/) {
        #works
        say "city is ",    $_ with $<city>.made;
        say "state is ",   $_ with $<state-zip><state>.made;
        say "zipcode is ", $_ with $<state-zip><zipcode>.made;

        #doesn't work
        say "state2 is ",   $_ with $<state>.made;
        say "zipcode2 is ", $_ with $<zipcode>.made;
    }

    method city($/)     { make ~$/ }
    method state($/)    { make ~$/ }
    method zipcode($/)  { make ~$/ }
}

my $address = q:to/END/;
Springfield,
IL 62704
END

Grammar.parse($address, :actions(Actions));

效果很好：

TOP
|  city
|  * MATCH "Springfield,"
|  state-zip
|  |  state
|  |  * MATCH "IL"
|  |  zipcode
|  |  * MATCH "62704"
|  * MATCH "IL 62704"
city is Springfield,
state is IL
zipcode is 62704
* MATCH "Springfield,\nIL 62704\n"

token <state-zip>是让状态和邮政编码共存于一行还是跨越多行。请记住，这是一个 MRE，因此我正在寻找不会改变语法的答案，但会改变操作的 make / made 方面。

但是 - 为了简化我的代码，我希望能够从method TOP($/) {}我的示例 state2 和 zipcode2 的操作中访问顶层的州和邮政编码。我一直在尝试将状态和令牌的制作值“提升”到匹配树上 - 例如可能是这样的：

# doesn't work
method TOP($/) {
    make $<state>.made;
    make $<zip>.made;
    ...
}
method state-zip($/) {
    make $<state>.made;
    make $<zip>.made;
}

这可能吗？

parsing