Jalaj P. Jha Technical & Miscellaneous Ramblings

Logo – Turtle Graphics!?

I learnt Logo (Turtle Graphics) when I was in class 8th (that was 1987, today children are taught Logo in their primary classes). For those who are not aware of, Logo is an Interpreted language, the turtle graphics of which is considered most apt language for young students to learn. Students can learn to program movement of on-screen turtle drawing basic shapes and fractal pattens.

Now when my son's exams were over yesterday (he passed KinderGarten!), and being already fed up with his old computer games, Feeding Frenzy and SuperTux, recalled my promise to bring for him the Turtle Graphics software. I remembered he was asking for SpiderMan game and my system being too slow for it, I just mentioned Logo and turtle, and he seems not to have forgotten it…

So now I sat down searching for a Logo Software and got references to three, the third one being the one with latest release (ver.6.13.0 on 18-02-2007)

1. Berkeley Logo (UCBLogo)
2. MSWLogo
3. FMSLogo

While till now I thought Logo to be just Turtle Graphics the following lines on FMSLogo documentation Caught My Eye

FMSLogo includes support for
- Exception handling
- TCP/IP networking
- Direct I/O for controlling external hardware (must be admin)
- Serial and parallel port communications
- Calling into native DLLs
- Creating windows dialog boxes
- Event driven programming (mouse, keyboard, timer)
- Controlling multimedia devices (WAV sound files, CD-ROM control, etc.)
- 3D Perspective drawing (wire-frame and solids)
- Creating animated GIFs
(A few lines deleted here to focus on the ones I am surprised for)

So, contrary to my belief, Logo is not just a Child's play...

A sample program and supporting commentary taken from Berkly Logo site

Here is a short but complete program in Berkeley Logo: 

to choices :menu [:sofar []]
if emptyp :menu [print :sofar stop]
foreach first :menu [(choices butfirst :menu sentence :sofar ?)]
end

And here's how you use it. You type

choices [[small medium large]
         [vanilla [ultra chocolate] lychee [rum raisin] ginger]
         [cone cup]]

and Logo replies 

small vanilla cone
small vanilla cup
small ultra chocolate cone
small ultra chocolate cup
small lychee cone
small lychee cup
small rum raisin cone
small rum raisin cup
small ginger cone
small ginger cup
medium vanilla cone
medium vanilla cup
medium ultra chocolate cone
medium ultra chocolate cup
medium lychee cone
medium lychee cup
medium rum raisin cone
medium rum raisin cup
medium ginger cone
medium ginger cup
large vanilla cone
large vanilla cup
large ultra chocolate cone
large ultra chocolate cup
large lychee cone
large lychee cup
large rum raisin cone
large rum raisin cup
large ginger cone
large ginger cup

The program doesn't have anything about the size of the menu built in.
You can use any number of categories, and any number of possibilities in each category.
Let's see you do that in four lines of Java!

All links provided above contain links to useful sites and documents related to Logo.