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| author | mkersten <mkersten> | 2003-07-14 12:58:42 +0000 |
|---|---|---|
| committer | mkersten <mkersten> | 2003-07-14 12:58:42 +0000 |
| commit | cc57abb7456100c16eb009707293d41d1f760db3 (patch) | |
| tree | d8c2915eceda262ceb5808aa7aa8da0f7d9d5d6b /docs/developer/overview.html | |
| parent | 461bf788adbc4e7740202ea4c1866268f312d4b1 (diff) | |
| download | aspectj-cc57abb7456100c16eb009707293d41d1f760db3.tar.gz aspectj-cc57abb7456100c16eb009707293d41d1f760db3.zip | |
Finally adding some design docs (after 4 years).
Diffstat (limited to 'docs/developer/overview.html')
| -rw-r--r-- | docs/developer/overview.html | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/docs/developer/overview.html b/docs/developer/overview.html new file mode 100644 index 000000000..fdd7520d6 --- /dev/null +++ b/docs/developer/overview.html @@ -0,0 +1,174 @@ +<html> + +<head> +<meta http-equiv="Content-Language" content="en-us"> +<meta http-equiv="Content-Type" content="text/html; charset=windows-1252"> +<meta name="GENERATOR" content="Microsoft FrontPage 5.0"> +<meta name="ProgId" content="FrontPage.Editor.Document"> +<title>AJDT Project Proposal</title> +<STYLE TYPE="text/css"> +<!-- + + /* FOR THE SDA PAGE */ + + /* + BODY {margin-top: 15px; margin-left: 15px; margin-right: 15px;} + */ + + A:link { + color:#4756AC; + } + A:visited { + color:#60657B; + } + A:hover { + color:red + } + + INPUT {font:12px "Courier New", sans-serif;} + + H2 { + font:18px/18px Verdana, Arial, Helvetica, sans-serif; + color:black; + font-weight:bold; + margin-left: 10px; + line-height:110%; + } + H3 { + font:18px/18px Verdana, Arial, Helvetica, sans-serif; + color:black; + font-weight:bold; + margin-left: 10px; + line-height:110%; + } + H4 { + font:15px/16px Verdana, Arial, Helvetica, sans-serif; + color:black; + font-weight:bold; + margin-left: 10px; + line-height:140%; + } + P { + font:13px/13px Verdana, Arial, Helvetica, sans-serif; + margin-right: 10px; + margin-left: 10px; + line-height:130%; + } + .paragraph { + font:13px/13px Verdana, Arial, Helvetica, sans-serif; + margin-right: 10px; + margin-left: 10px; + line-height:130%; + } + .smallParagraph { + font:11px/11px Verdana, Arial, Helvetica, sans-serif; + margin-right: 10px; + margin-left: 10px; + line-height:130%; + } + LI { + font:13px/13px Verdana, Arial, Helvetica, sans-serif; + text-align:justify; + margin-right: 10px; + margin-left: 15px; + line-height:120%; + } + /* + UL { + font:13px/13px Verdana, Arial, Helvetica, sans-serif; + text-align:justify; + margin-right: 10px; + margin-left: 15px; + line-height:120%; + }*/ + + DL { + font:13px/13px Verdana, Arial, Helvetica, sans-serif; + text-align:justify; + margin-right: 10px; + margin-left: 15px; + line-height:120%; + } + B { font:13px/13px Verdana, Arial, Helvetica, sans-serif; + font-weight:bold; + line-height:140%; + } + .footer { + font:10px/10px Verdana, Arial, Helvetica, sans-serif; + color:#888888; + text-align:left + } + .figureTitle { + font:13px/13px Verdana, Arial, Helvetica, sans-serif; + text-align:justify; + text-align:center + } + .copyrightNotice { + font:10px/10px Verdana, Arial, Helvetica, sans-serif; + color:#999999; + line-height:110%; + } + .smallHeading { + font:13px/13px Verdana, Arial, Helvetica, sans-serif; + font-weight:bold; + line-height:110%; + } + .tinyHeading { + font:11px/11px Verdana, Arial, Helvetica, sans-serif; + font-weight:bold; + line-height:120%; + } + .newsText { + font:11px/11px Verdana, Arial, Helvetica, sans-serif; + line-height:130%; + } + .smallParagraph { + font:11px/11px Verdana, Arial, Helvetica, sans-serif; + line-height:130%; + } + .fancyHeading { + font:20px/20px Chantilly, Arial, Helvetica, sans-serif; + margin-right: 10px; + color:#6f7a92; + margin-left: 10px; + line-height:130%; + } + +--> +</STYLE> +</head> + +<BODY BGCOLOR="white"> + +<h3 align="center">AspectJ Design Overview</h3> + +<h4 class="paragraph">Here are some sobering words from David Parnas on +"Ignorant Surgery" in his paper on Software Aging:</h4> +<h4 class="smallParagraph">"Although it is essential to upgrade software to +prevent aging, changing software can cause a different form of aging. The +designer of a piece of software usually had a simple concept in mind when +writing the program. If the program is large, understanding the concept allows +one to find those sections of the program that must be altered when an update or +correction is needed. Understanding that concept also implies understanding the +interfaces used within the system and between the system and its environment. +Changes made by people who do not understand the original design concept almost +always cause the structure of the program to degrade. Under those circumstances, +changes will be inconsistent with the original concept; in fact, they will +invalidate the original concept. Sometimes the damage is small, but often it is +quite severe. After those changes, one must know both the original design rules +and the newly introduced exceptions to the rules, to understand the product. +After many such changes, the original designers no longer understand the +product. Those who made the changes, never did. In other words, *nobody* +understands the modified product.<br> +Software that has been repeatedly modified (maintained) in this way becomes very +expensive to update. Changes take longer and are more likely to introduce new +'bugs'"</h4> +<h4>Contents</h4> +<ul> + <li><a href="modules.html">Module Structure</a></li> + <li><a href="language.html">Language Design</a></li> +</ul> + +</body> + +</html>
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