Structural Equivalent
The JSP version of the program is structurally equivalent to
String line; line = in.readLine; while (line != null) { int count = 0; String firstLineOfGroup = line; while (line != null && line.equals(firstLineOfGroup)) { count++; line = in.readLine; } System.out.println(firstLineOfGroup + " " + count); }and the traditional version of the program is equivalent to
String line; int count = 0; String firstLineOfGroup = null; while ((line = in.readLine) != null) { if (firstLineOfGroup == null || !line.equals(firstLineOfGroup)) { if (firstLineOfGroup != null) { System.out.println(firstLineOfGroup + " " + count); } count = 0; firstLineOfGroup = line; } count++; } if (firstLineOfGroup != null) { System.out.println(firstLineOfGroup + " " + count); }Jackson criticises the traditional version, claiming that it hides the relationships which exist between the input lines, compromising the program's understandability and maintainability by, for example, forcing the use of a special case for the first line and forcing another special case for a final output operation.
Read more about this topic: Jackson Structured Programming
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