A Tinker’s Trade - Lauren Ipsum: A Story About Computer Science and Other Improbable Things - page 30

CIRCLE :
Go forward one inch ,
make a mark,
go back one inch ,
turn right one degree,
repeat three hundred sixty times.
Then she realized that she could make circles of any size she wanted. It was just like opening
the compass wider.
TWO-CIRCLE :
Go forward two inches ,
make a mark,
go back two inches ,
turn right one degree,
repeat three hundred sixty times.
“This is interesting. You're working really hard!” Tinker scratched his head. “But as it is, it's
no good.”
“Why?”
“People want to make lots of different circles,” he said. “I'll have to keep a lot of algorithms
of different sizes, just in case someone wants three-and-nine-thirteenths inches or four-and-
three-quarters inches.”
“Well, what if you tell the turtle how big to make the circle?” she said. “Maybe like this.”
ANY-CIRCLE ( how-big? ):
Go forward how-big? inches,
make a mark,
go back how-big? inches,
turn right one degree,
repeat three hundred sixty times.
“And then ,” she said, “instead of ONE-CIRCLE or TWO-CIRCLE, you can say ANY-
CIRCLE(one), or (two), or even (one-and-eleventy-sevenths)!”