Extremely basic turtle graphics interpreter & compiler, written in Go

This is my attempt to write a simplistic language interpreter and possibly compiler in Go yet with some basic use-case. This is how the turtle graphics interpreter/compiler was born.

The keywords

The language is very limited. It does not have support even for negative numbers :), there is no support for procedures but still has a basic loop implemented.

The available keywords (with the parameters) are here:

• home
• paper <black|white|red|green|blue|yellow|gray|magenta>
• ink <black|white|red|green|blue|yellow|gray|magenta>
• pen <down|up>
• repeat <number> <statemets> loop
• forward <number>
• back <number>
• left <number>
• right <number>

You can have a full line comment as well with # (see the example below)

Example of the logo source that draws a star

# This example will draw a star

paper black
ink white
home

back 100
left 90
back 160

pen down

repeat 18
	forward 50
	left 100
	forward 50
	right 120
loop

You can find additional sample in samples folder

How to run samples ?

You can find samples in samples folder and they can be run with the following command

To build the interpreter (uses GNU make)

make

You have to pipe the source code to the interpreter like so:

cat samples/star.logo | ./logo-visual 

Outputs

Star

Heart

Circles

The compiler

There is also a very basic compiler for HTML5 canvas and JavaScript. If you compare the interpreter and the compiler, you will find that they are very similar.

To build the compiler (uses GNU make)

make

To compile the source code to HTML5, use the command

cat samples/circles.logo | ./logo-compiler > output.html

Then you can view the output from any modern browser.

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The only dependecy is, used by the visualizer

https://github.com/veandco/go-sdl2