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 intelli-

gent solution to the problem. First, create a class

of breakfast foods. Specialize this class into sub-

classes: grains, pork, and poultry. The specializa-

tion process should be repeated with grains di-

vided 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 spe-

cial 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

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 implemen-

tation 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. (Imag-

ine 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 v2.14

by Barry R. Lee

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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