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XPro User Group News
(Con’t from Page 6)
recognized the danger of such short-sighted thinking. He said, “Toasters don’t just turn bread into toast, they are also used to warm frozen waffles. What you see before you is really a break- fast food cooker. As the subjects of your kingdom become more sophisticated, they will demand more capabilities. They will need a breakfast food cooker that can also cook sausage, fry bacon, and make scrambled eggs. A toaster that only makes toast will soon be obsolete. If we don’t look to the future, we will have to completely redesign the toaster in just a few years.”
“With this in mind, we can formulate a more intelligent solution to the problem. First, create a class of breakfast foods. Specialize this class into sub- classes: grains, pork, and poultry. The specialization process should be repeated with grains divided into toast, muffins, pancakes, and waffles; pork divided into sausage, links, and bacon; and poultry divided into scrambled eggs, hard- boiled eggs, poached eggs, fried eggs, and various omelet classes.”
“The ham and cheese omelet class is worth special attention because it must inherit characteristics from the pork, dairy, and poultry classes. Thus, we see that the problem cannot be properly solved without multiple inheritance. At run time, the program must create the proper object and send a message to the object that says, 'Cook yourself.’ The semantics of this message depend, of course, on the kind of object, so they have a different meaning to a piece of toast than to scrambled eggs.”
“Reviewing the process so far, we see that the analysis phase has revealed that the primary requirement is to cook any kind of breakfast food. In the design phase, we have discovered some derived requirements. Specifically, we need an object-oriented language with multiple inheritance. Of course, users don’t want the eggs to get cold while the bacon is frying, so concurrent processing is required, too.”
“We must not forget the user interface. The lever that lowers the food lacks versatility, and the darkness knob is confusing. Users won’t buy the product unless it has a user-friendly, graphical
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interface. When the breakfast cooker is plugged in, users should see a cowboy boot on the screen. Users click on it, and the message ‘Booting UNIX v.8.3’ appears on the screen. (UNIX 8.3 should be out by the time the product gets to the market.) Users can pull down a menu and click on the foods they want to cook.”
“Having made the wise decision of specifying the software first in the design phase, all that remains is to pick an adequate hardware platform for the implementation phase. An Intel 80486 with 16MB of memory, a 300MB hard disk, and a VGA monitor should be sufficient. If you select a multitasking, object oriented language that supports multiple inheritance and has a built-in GUI, writing the program will be a snap. (Imagine the difficulty we would have had if we had foolishly allowed a hardware-first design strategy to lock us into a four-bit microcontroller!).”
The king wisely had the computer scientist beheaded, and they all lived happily ever after.
FoxFinder Version 2.14 was recently uploaded to the FoxForum on CompuServe by author Michael Bolser. If you are not familiar with FoxFinder you may want to give it a try. This freeware utility is a search and/or replace utility that runs within FoxPro. It can search and replace text in screens, menus, reports, labels, databases and any ASCII file including queries.
Some of the features of FoxFinder are:
Search mode lists file that contains the specified search text. This includes a description of where the text was found and the number of occurences. Plus you can double click any of the file names and FoxFinder will open an edit window on that file. Reverse mode for a listing of files that do not include specified text. Searches all code snippets and memo fields. User can designate search directories by file type. Option to save and restore settings. User- definable File Types
This great little utility is well designed and easy to use It supports both DOS and Windows with an interface customized for each enviomment. If you ever needed to search and replace across a project, this little utility will do it.
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