不能在 `qqww` 或 `qqww:to` 结构中使用冒号对

Question

我想使用 Class 生成 json 行，我覆盖了 gist 方法，以便它打印我想要的内容：

my $ak = '7111ac873c9dcd5fc335ded47630d050';
my $st = '1523451601875';
my $ifo = 'true';
my $uu = "15778787898988090";

class Stay {
  has $.ak  is rw = '7111ac873c9dcd5fc335ded47630d050';
  has $.uu  is rw;
  has $.ifo is rw;
  has $.st  is rw;

  method gist() {
    #return qqww/{"ev":"app","ak":"$!ak","uu":"$!uu","ifo":"$!ifo","st":"$!st"}/;

    return qqww:to「EOF」;
    {"ev":"app","ak":"$!ak","uu":"$!uu","ifo":"$!ifo","st":"$!st"}
    EOF
  }
}

say Stay.new(uu => $uu, ifo => $ifo, st => $st);

但失败：

===SORRY!=== Error while compiling /Users/ohmycloud/Desktop/stay.pl6
Confused
at /Users/ohmycloud/Desktop/stay.pl6:18
------>     {"ev":⏏"app","ak":"$!ak","uu":"$!uu","ifo":"$!i
    expecting any of:
        colon pair

我想要的是：

{"ev":"app","ak":"7111ac873c9dcd5fc335ded47630d050","uu":"15778787898988090","ifo":"true","st":"1523451601875"}

为什么我不能在 qqww 或 qq:to 结构中使用冒号对？

Answer 1

您可以使用 unquoting:

method gist() {
    return '{"ev":"app","ak":"\qq[$!ak]","uu":"\qq[$!uu]","ifo":"\qq[$!ifo]","st":"\qq[$!st]"}':
}

这将 return

{"ev":"app","ak":"7111ac873c9dcd5fc335ded47630d050","uu":"15778787898988090","ifo":"true","st":"1523451601875"}

如果您使用 qqww 或类似的，冒号会妨碍您。

Answer 2

{} 在双引号中有特殊含义。它们必须被转义

qq:to「EOF」;
\{"ev":"app","ak":"$!ak","uu":"$!uu","ifo":"$!ifo","st":"$!st"\}
EOF

你需要 qq，而不是 qqww 来制作列表。

您可以使用fmt

(:ev<app>, :$!ak, :$!uu, :$!ifo, :$!st).fmt('"%s":"%s"', ',').fmt('{%s}')

或JSON::Fast

require JSON::Fast <&to-json>;
{:ev<app>, :$!ak, :$!uu, :$!ifo, :$!st}.&to-json

甚至

require JSON::Fast <&to-json>;
self.^attributes.map( {.name => .get_value(self)} ).Hash.&to-json

不能在 `qqww` 或 `qqww:to` 结构中使用冒号对

can't use colon pair in `qqww` or `qqww:to` struct

raku