use Smart::Comments が便利すぎる
use Smart::Comments; が便利すぎるので、主要な部分をかなり適当に意訳しました。
原文も載せておきますので、「ここおかしい」「この訳のほうが適切」という箇所を見つけた場合、報告していただけるとありがたいです。
NAME
Smart::Comments - Comments that do more than just sit there
Smart::Comments - おい…このコメント、動くぞッ…！？
VERSION
This document describes Smart::Comments version 1.0.4
SYNOPSIS
use Smart::Comments; my $var = suspect_value(); ### $var ### got: $var ### Now computing value... # and when looping: for my $big_num (@big_nums) { ### Factoring... done factor($big_num); } while ($error > $tolerance) { ### Refining---> done refine_approximation() } for (my $i=0; $i<$MAX_INT; $i++) { ### Working===[%] done do_something_expensive_with($i); }
DESCRIPTION
Smart comments provide an easy way to insert debugging and tracking code into a program. They can report the value of a variable, track the progress of a loop, and verify that particular assertions are true.
Smart commentsはプログラムに用意にデバッギング/トラッキングコードを用意に挿入する手段を提供します。変数の値や、ループの進捗を表示したり、特定のアサーションがtrueであることを確かめます。
Best of all, when you're finished debugging, you don't have to remove them. Simply commenting out the use Smart::Comments line turns them back into regular comments. Leaving smart comments in your code is smart because if you needed them once, you'll almost certainly need them again later.
デバッグが終了したとき、それらのコメントを削除する必要はありません。 use Smart::Commentsを単に普通のコメントに戻してしまえばおｋ。スマートコメントをコードの中に残しておくと良いでしょう。なぜなら、一度必要になったものは、今後きっと必要になるでしょうから。
INTERFACE
All smart comments start with three (or more) # characters. That is, they are regular #-introduced comments whose first two (or more) characters are also #'s.
全てのスマートコメントは３つ（あるいはそれ以上の） # から始まります。つまり、ふつーの#で始まるコメントとかわらないですよ。
Using the Module
モジュールを使う
The module is loaded like any other:
このモジュールは次のようにロードされるよ：
use Smart::Comments;
When loaded it filters the remaining code up to the next:
次のno Smart::Comments;文が実行されるまでのコードをフィルタリングするよ
no Smart::Comments;
directive, replacing any smart comments with smart code that implements the comments behaviour.
コメントの振る舞いを実行するスマートコードを含むスマートコメントを置き換えるよ。
If you're debugging an application you can also invoke it with the module from the command-line:
デバッグ中のアプリケーションをコマンドラインから実行したい時は次のようにも書けるよ：
perl -MSmart::Comments $application.pl
Of course, this only enables smart comments in the application file itself, not in any modules that the application loads.
もちろん、これはアプリケーションファイルそのものだけでスマートコメントが有効になるので、アプリケーションが読み込むモジュールでは有効にならないよ。
You can also specify particular levels of smartness, by including one or more markers as arguments to the use:
useするときにひとつ以上のマーカーを含めて引数として渡せば、特定のレベルの#の数を決められるよ。
use Smart::Comments '###', '####';
These arguments tell the module to filter only those comments that start with the same number of #'s. So the above use statement would "activate" any smart comments of the form:
上記の引数は同数の#で始まるコメントのみをフィルターするようにモジュールに伝えているよ。つまり、上記のuse文は次に挙げるスマートコメントの形式を有効にしますよ。
### Smart... #### Smarter...
but not those of the form:
だけども、下記の形式は有効になりませよ。
##### Smartest...
This facility is useful for differentiating progress bars (see "Progress Bars"), which should always be active, from debugging comments (see "Debugging via Comments"), which should not:
この機能はプログレスバー（常にアクティブ）とデバッギングコメント（常にアクティブでない）ものを区別するのに役に立ちます。
#### Debugging here... for (@values) { ### Progress: 0... 100 do_stuff(); }
Note that, for simplicity, all smart comments described below will be written with three #'s; in all such cases, any number of #'s greater than three could be used instead.
注意。単純化するために、これから下に書かれている説明では###で書かれているけれども、上記のようなケースで、#みっつ以上でのスマートコメントが代わりに使われることもあるよ。
Debugging via Comments
コメントを通してデバッグする
The simplest way to use smart comments is for debugging. The module supports the following forms, all of which print to STDERR:
一番単純なスマートコメントの使い道はデバッギング。このモジュールは次の形式をサポートしていて、すべての出力はSTDERRです：
### LABEL : EXPRESSION
The LABEL is any sequence of characters up to the first colon. The EXPRESSION is any valid Perl expression, including a simple variable. When active, the comment prints the label, followed by the value of the expression. For example:
LABELは最初のコロンが出るまでの文字列ですよ。EXPRESSIONは単純な変数を含むPerlの有効な式です。アクティブなとき、コメントはラベルとそれに続く式を表示しますよ。例えば、
### Expected: 2 * $prediction ### Got: $result
prints:
### Expected: 42 ### Got: 13
### EXPRESSION
The EXPRESSION is any valid Perl expression, including a simple variable. When active, the comment prints the expression, followed by the value of the expression. For example:
EXPRESSIONは単純な変数を含むPerlの有効な式ですよ。アクティブなとき、式とそれに続く式の値を表示します。例えば、
### 2 * $prediction ### $result
prints:
### 2 * $prediction: 42 ### $result: 13
### TEXT...
The TEXT is any sequence of characters that end in three dots. When active, the comment just prints the text, including the dots. For example:
TEXTは３つのドットで終わる文字列です。アクティブな時に、ドットを含んだ形でテキストを表示しますよ。例えば、
### Acquiring data... $data = get_data(); ### Verifying data... verify_data($data); ### Assimilating data... assimilate_data($data); ### Tired now, having a little lie down... sleep 900;
would print:
### Acquiring data... ### Verifying data... ### Assimilating data... ### Tired now, having a little lie down...
as each phase commenced. This is particularly useful for tracking down precisely where a bug is occurring. It is also useful in non-debugging situations, especially when batch processing, as a simple progress feedback mechanism.
フレーズが始まるごとに表示すれば、バグが起こっている正確な場所を追跡するのに役立つよ。同様に、デバッグ中でなくても、バッチ処理のようにシンプルな処理のフィードバックとして役立ちますね。
Within a textual smart comment you can use the special sequence
### [<now>] Acquiring data...
would produce something like:
### [Fri Nov 18 15:11:15 EST 2005] Acquiring data...
There are also "spacestamps":
同様に、
### Acquiring data at <loc>...
to produce something like:
### Acquiring data at "demo.pl", line 7...
You can, of course, use both in the same comment as well.
Checks and Assertions via Comments
コメントを通してチェックとアサーション
### require: BOOLEAN_EXPR ### assert: BOOLEAN_EXPR ### ensure: BOOLEAN_EXPR ### insist: BOOLEAN_EXPR
These four are synonyms for the same behaviour. The comment evaluates the expression in a boolean context. If the result is true, nothing more is done. If the result is false, the comment throws an exception listing the expression, the fact that it failed, and the values of any variables used in the expression.
これらの４つは同じ振る舞いをするものの別称です。コメントは式をブールのコンテキストとして評価しますよ。結果が真の場合、何も実行されません。偽の場合、例外を投げて、式が失敗した事実、式の中で使われた変数を列挙します。
For example, given the following assertion:
例えば、
### require: $min < $result && $result < $max
if the expression evaluated false, the comment would die with the following message:
式が偽と評価された場合、次のメッセージと共にdieします
### $min < $result && $result < $max was not true at demo.pl line 86. ### $min was: 7 ### $result was: 1000004 ### $max was: 99
### check: BOOLEAN_EXPR ### confirm: BOOLEAN_EXPR ### verify: BOOLEAN_EXPR
These three are synonyms for the same behaviour. The comment evaluates the expression in a boolean context. If the result is true, nothing more is done. If the result is false, the comment prints a warning message listing the expression, the fact that it failed, and the values of any variables used in the expression.
これらの３つは同じ振る舞いをするものの別称です。コメントは式をブールのコンテキストとして評価しますよ。結果が真の場合、何も実行されません。偽の場合は、式と、失敗した事実、式の中で使われた変数を警告文として列挙します。
The effect is identical to that of the four assertions listed earlier, except that warn is used instead of die.
前述の４つのものとは、dieの変わりにwarnが使われる点を除けば、影響としては同等です。
Progress Bars
You can put a smart comment on the same line as any of the following types of Perl loop:
次に列挙されているタイプのPerlループの同じ行にスマートコメントをかけますよ。
foreach my VAR ( LIST ) { ### Progressing... done for my VAR ( LIST ) { ### Progressing... done foreach ( LIST ) { ### Progressing... done for ( LIST ) { ### Progressing... done while (CONDITION) { ### Progressing... done until (CONDITION) { ### Progressing... done for (INIT; CONDITION; INCR) { ### Progressing... done
In each case, the module animates the comment, causing the dots to extend from the left text, reaching the right text on the last iteration. For "open ended" loops (like while and C-style for loops), the dots will never reach the right text and their progress slows down as the number of iterations increases.
それぞれのケースで、このモジュールはドットを起点として右のテキストまでコメントを動的に表示します。"open ended"ループ（whileやCスタイルのforループ）では決して右側のテキストには到達せず、プログレスバーは反復が増えるにしたがって遅くなりますよ。
For example, a smart comment like:
例えば、このようなスマートコメントでは
for (@candidates) { ### Evaluating... done
would be animated is the following sequence (which would appear sequentially on a single line, rather than on consecutive lines):
下記のように動的に表示します。（連続した複数行ではなく、１行で表示されます）
Evaluating done
Evaluating...... done
Evaluating............. done
Evaluating................... done
Evaluating..........................done
The module animates the first sequence of three identical characters in the comment, provided those characters are followed by a gap of at least two whitespace characters. So you can specify different types of progress bars. For example:
このモジュールはコメント内のはじめにある３つの連続した文字列と少なくとも2つのスペースでに続く文字列を動的に描画します。よって、異なった種類のプログレスバーを指定できますよ。例えば、
for (@candidates) { ### Evaluating::: done
or:
for (@candidates) { ### Evaluating=== done
or:
for (@candidates) { ### Evaluating||| done
If the characters to be animated are immediately followed by other non-whitespace characters before the gap, then those other non-whitespace characters are used as an "arrow head" or "leader" and are pushed right by the growing progress bar. For example:
スペースでない文字を動的に描画されるものの直後（スペースの前）につけると、矢印やリーダーがプログレスバーの右端に追加されますよ。例えば、
for (@candidates) { ### Evaluating===| done
would animate like so:
Evaluating| done
Evaluating=====| done
Evaluating============| done
Evaluating==================| done
Evaluating==========================done
If a percentage character (%) appears anywhere in the comment, it is replaced by the percentage completion. For example:
"%"は進捗具合を表示します。例えば、
for (@candidates) { ### Evaluating [===| ] % done
animates like so:
Evaluating [| ] 0% done Evaluating [===| ] 25% done Evaluating [========| ] 50% done Evaluating [============| ] 75% done Evaluating [=================] 100% done
If the % is in the "arrow head" it moves with the progress bar. For example:
for (@candidates) { ### Evaluating |===[%] |
would be aninated like so:
Evaluating |[0%] | Evaluating |=[25%] | Evaluating |========[50%] | Evaluating |===============[75%] | Evaluating |===========================|
For "open-ended" loops, the percentage completion is unknown, so the module replaces each % with the current iteration count. For example:
"open-ended"ループの場合は、進捗度は未知であるため、%は現在の反復回数を表示します。例えば、
while ($next ne $target) { ### Evaluating |===[%] |
would animate like so:
Evaluating |[0] | Evaluating |=[2] | Evaluating |==[3] | Evaluating |===[5] | Evaluating |====[7] | Evaluating |=====[8] | Evaluating |======[11] |
Note that the non-sequential numbering in the above example is a result of the "hurry up and slow down" algorithm that prevents open-ended loops from ever reaching the right-hand side.
注意。上記のような連続的でないナンバリングのサンプルはopen-endedループが右端に達するのを防ぐための、「はじめは早く、だんだんゆっくり」カウントするアルゴリズムによる結果ですよ。
As a special case, if the progress bar is drawn as two pairs of identical brackets:
特別なケースとして、二つの特定のペアのブラケットで描画されますよ。
for (@candidates) { ### Evaluating: [][] for (@candidates) { ### Evaluating: {}{} for (@candidates) { ### Evaluating: ()() for (@candidates) { ### Evaluating: <><>
Then the bar grows by repeating bracket pairs:
こうした場合、バーはブラケットペアの繰り返しとして表示されます：
Evaluating: [ Evaluating: [] Evaluating: [][ Evaluating: [][] Evaluating: [][][
etc.
Finally, progress bars don't have to have an animated component. They can just report the loop's progress numerically:
最後に、プログレスバーは動的に描画される必要はなく、単にループのの進捗を数字で示すこともできますよ：
for (@candidates) { ### Evaluating (% done)
which would animate (all of the same line):
全て同じ行で描画されます：
Evaluating (0% done) Evaluating (25% done) Evaluating (50% done) Evaluating (75% done) Evaluating (100% done)
Time-Remaining Estimates
When a progress bar is used with a for loop, the module tracks how long each iteration is taking and makes an estimate of how much time will be required to complete the entire loop.
プログレスバーがforループで使われた時、このモジュールは反復がどれくらいかかるかを把握し、ループ全体が必要とする時間を計算します。
Normally this estimate is not shown, unless the estimate becomes large enough to warrant informing the user. Specifically, the estimate will be shown if, after five seconds, the time remaining exceeds ten seconds. In other words, a time-remaining estimate is shown if the module detects a for loop that is likely to take more than 15 seconds in total. For example:
ユーザに知らせる根拠があるほど長くならない場合、通常はこの計算は表示されませんよ。とりわけ、10秒以上処理時間が残っている場合は5秒後に計算された時間が表示されます。言い換えれば、forループが合計で15秒以上かかると推定された場合に表示されますよ。例えば、
for (@seven_samurai) { ### Fighting: [||| ] fight(); sleep 5; }
would be animated like so:
Fighting: [ ] Fighting: [|||| ] Fighting: [||||||||| ] (about 20 seconds remaining) Fighting: [|||||||||||||| ] (about 20 seconds remaining) Fighting: [|||||||||||||||||| ] (about 10 seconds remaining) Fighting: [||||||||||||||||||||||| ] (less than 10 seconds remaining) Fighting: [|||||||||||||||||||||||||||]
The precision of the reported time-remaining estimate is deliberately vague, mainly to prevent it being annoyingly wrong.
主に、うっとうしい誤りを防ぐために、報告された残り時間の正確さは故意にあいまいにしてありますよ。
DIAGNOSTICS
In a sense, everything this module does is a diagnostic. All comments that print anything, print it to STDERR.
However, the module itself has only one diagnostic:
Incomprehensible arguments: %s in call to 'use Smart::Comments
You loaded the module and passed it an argument that wasn't three-or- more #'s. Arguments like '###', '####', '#####', etc. are the only ones that the module accepts.
CONFIGURATION AND ENVIRONMENT
Smart::Comments can make use of an environment variable from your shell: Smart_Comments. This variable can be specified either with a true/false value (i.e. 1 or 0) or with the same arguments as may be passed on the use line when loading the module (see "INTERFACE"). The following table summarizes the behaviour:
Value of
$ENV{Smart_Comments} Equivalent Perl
1 use Smart::Comments;
0 no Smart::Comments;
'###:####' use Smart::Comments qw(### ####);
'### ####' use Smart::Comments qw(### ####);
To enable the Smart_Comments environment variable, you need to load the module with the -ENV flag:
use Smart::Comments -ENV;
Note that you can still specify other arguments in the use statement:
use Smart::Comments -ENV, qw(### #####);
In this case, the contents of the environment variable replace the -ENV in the argument list.
DEPENDENCIES
The module requires the following modules:
* Filter::Simple
* version.pm
* List::Util
* Data::Dumper
* Text::Balanced
INCOMPATIBILITIES
None reported. This module is probably even relatively safe with other Filter::Simple modules since it is very specific and limited in what it filters.
BUGS AND LIMITATIONS ^
No bugs have been reported.
This module has the usual limitations of source filters (i.e. it looks smarter than it is).
Please report any bugs or feature requests to bug-smart-comments@rt.cpan.org, or through the web interface at http://rt.cpan.org.
AUTHOR
Damian Conway
LICENCE AND COPYRIGHT ^
Copyright (c) 2005, Damian Conway . All rights reserved.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
DISCLAIMER OF WARRANTY ^
BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.
IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
