quote-interpolation.p6

use v6;

# by nine

class SQLValue {
    has $.str;
    method Str() { "quoted(" ~ $.str.Str ~ ")" }
};

multi sub infix:<~>(Str:D $str, SQLValue:D $val) { $str ~ $val.Str }

sub prefix:<sql>(&block) {
    my @stringy;
    my @handler;

    @stringy = Mu.^find_method("Stringy"), Str.^find_method("Stringy");
    @handler = @stringy».wrap(sub ($self) { SQLValue.new(:str($self)) }) };

    LEAVE for @stringy Z @handler -> $method, $handler { $method.unwrap($handler) };

    &block()
}

my $foo = 42;
my $bar = "bar";
say sql{ "foo=$foo or $bar" }