Implementing Turtle Graphics...

Abstract

Turtle Graphics were invented by Seymour Papert in the 1960’s and form the best known part of his introductory programming language, Logo. The idea is that lines can be drawn on the screen by an (imaginary) turtle which happens to be carrying a pen around with it. It can be commanded to head off in any given direction, travel a specific distance, lower the pen so that it leaves a track as it goes, or raise it so that no trace is left. In some implementations the turtle is a robot, and the name is more appropriate, but the side effects on carpets can be undesirable.

“Once,” said the Mock Turtle at last, with a deep sigh,“ I was a real Turtle.”

Alice’s Adventures in Wonderland