名前¶

autouse - postpone load of modules until a function is used

autouse - 関数が使われるまでモジュールの読み込みを延期する

概要¶

  use autouse 'Carp' => qw(carp croak);
  carp "this carp was predeclared and autoused ";

説明¶

If the module Module is already loaded, then the declaration

モジュール Module が既に読み込まれていれば、以下の宣言は

  use autouse 'Module' => qw(func1 func2($;$));

is equivalent to

以下と等価です

  use Module qw(func1 func2);

if Module defines func2() with prototype ($;$), and func1() has no prototypes. (At least if Module uses Exporter's import, otherwise it is a fatal error.)

Module で、プロトタイプ ($;$) で func2() を、プロトタイプなしで func1() を定義している場合です。 (少なくとも Module が Exporter の import を使っている場合です; さもなければ致命的エラーになります。)

If the module Module is not loaded yet, then the above declaration declares functions func1() and func2() in the current package. When these functions are called, they load the package Module if needed, and substitute themselves with the correct definitions.

モジュール Module がまだ読み込まれていない場合、上述の宣言は現在のパッケージの関数 func1() と func2() を宣言します。これらの関数が呼び出されると、必要ならパッケージが Module が読み込まれ、正しい定義と置き換えられます。

WARNING¶

Using autouse will move important steps of your program's execution from compile time to runtime. This can

Using autouse will move important steps of your program's execution from compile time to runtime. This can (TBT)

Break the execution of your program if the module you autoused has some initialization which it expects to be done early.

Break the execution of your program if the module you autoused has some initialization which it expects to be done early. (TBT)
hide bugs in your code since important checks (like correctness of prototypes) is moved from compile time to runtime. In particular, if the prototype you specified on autouse line is wrong, you will not find it out until the corresponding function is executed. This will be very unfortunate for functions which are not always called (note that for such functions autouseing gives biggest win, for a workaround see below).

hide bugs in your code since important checks (like correctness of prototypes) is moved from compile time to runtime. In particular, if the prototype you specified on autouse line is wrong, you will not find it out until the corresponding function is executed. This will be very unfortunate for functions which are not always called (note that for such functions autouseing gives biggest win, for a workaround see below). (TBT)

To alleviate the second problem (partially) it is advised to write your scripts like this:

To alleviate the second problem (partially) it is advised to write your scripts like this: (TBT)

  use Module;
  use autouse Module => qw(carp($) croak(&$));
  carp "this carp was predeclared and autoused ";

The first line ensures that the errors in your argument specification are found early. When you ship your application you should comment out the first line, since it makes the second one useless.

The first line ensures that the errors in your argument specification are found early. When you ship your application you should comment out the first line, since it makes the second one useless. (TBT)

作者¶

Ilya Zakharevich ([email protected])

名前¶

概要¶

説明¶

WARNING¶

作者¶

SEE ALSO¶