我只是开始上课,所以我不了解基础知识.
class TEST {
has Str $.str;
method reg {
return
rx/
<<
<[abc]> *
$!str
<!before foo>
/;
}
}
my $var = TEST.new(str => 'baz');
say $var.reg;
尝试运行此程序时,我收到以下错误消息：
===SORRY!=== Error while compiling /home/evb/Desktop/p6/e.p6
Attribute $!str not available inside of a regex,since regexes are methods on Cursor.
Consider storing the attribute in a lexical,and using that in the regex.
at /home/evb/Desktop/p6/e.p6:11
------> <!before foo>⏏<EOL>
expecting any of:
infix stopper
那么,这样做的正确方法是什么？
解决方法
看起来这样可行：
class TEST {
has Str $.str;
method reg {
my $str = $.str;
return
regex {
<<
<[abc]> *
$str
<!before foo>
}
}
}
my $var = TEST.new(str => 'baz');
say $var.reg;
say "foo" ~~ $var.reg;
say "<<abaz" ~~ $var.reg
你正在返回anonymous regex,它可以用作实际的正则表达式,就像它在最后两个句子中所做的那样.