perl - 为什么语法 `&name arg1 arg2 ...` 不能用于调用 Perl 子程序？

Question

对于 Perl 子程序，如果传递 0 个参数，我可以使用 4 种形式来调用它。但是如果传递 1 个或多个参数，则有一种形式我无法使用，请参见下文:

sub name
{
    print "hello\n";
}
# 4 forms to call
name;
&name;
name();
&name();

sub aname
{
        print "@_\n";
}
aname "arg1", "arg2";
#&aname "arg1", "arg2"; # syntax error
aname("arg1", "arg2");
&aname("arg1", "arg2");

错误输出是

String found where operator expected at tmp1.pl line 16, near "&aname "arg1""
    (Missing operator before  "arg1"?)
syntax error at tmp1.pl line 16, near "&aname "arg1""
Execution of tmp1.pl aborted due to compilation errors.

有人可以从编译器的角度解释错误输出吗？我不明白为什么它会提示缺少运算符(operator)。

谢谢

Answer 1

它记录在 perlsub 中:

To call subroutines:

       NAME(LIST);    # & is optional with parentheses.
       NAME LIST;     # Parentheses optional if predeclared/imported.
       &NAME(LIST);   # Circumvent prototypes.
       &NAME;         # Makes current @_ visible to called subroutine.

与 &NAME "arg" , perl 看到 &NAME() "ARG" ，所以它认为子调用和“ARG”之间缺少一个运算符。

在 Perl 5 中，您不需要 &大多数情况下。