为什么语法“&name arg1 arg2 ...”不能用于调用 Perl 子例程？

Question

对于一个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，有一种形式我不能使用，请看下面：

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");

错误输出为

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抱怨缺少运算符。

谢谢

Answer 1

它记录在 perlsub:

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.

对于 &NAME "arg"，perl 看到 &NAME() "ARG"，因此它认为在子调用和 "ARG" 之间缺少一个运算符。

在 Perl 5 中，大多数情况下您不需要 &。

为什么语法“&name arg1 arg2 ...”不能用于调用 Perl 子例程？

why the syntax `&name arg1 arg2 ...` can't be used to call a Perl subroutine?

perl

syntax

subroutine

invocation