CFR[]

CFR[] (CFR Brackets) is an extremely minimal drawing language that consists of only five simple commands:

• C: Change colour.
• F: Move forward by one cell and paint the new cell.
• R: Rotate right (clockwise) by 45°.
• [: Begin a repeatable block and continue executing subsequent code.
• ]: Repeat current repeatable block once more and exit the block.

Note that ] goes back to the beginning of the current repeatable block, repeats it once more, and exits the block. Thus a block bounded by [ and ] behaves like a loop that runs twice before the block exits.

CFR[] is a strict subset of CFRS[]. CFRS[] has an additional command named S which can be used to make the turtle sleep for a short duration. CFR[] does not have the S command. This is the only difference between CFR[] and CFRS[]. Therefore, for a complete description of CFR[], see CFRS[] instead but disregard any information pertaining to the S command.

To play with CFR[], go to susam.net/cfr.html.

To play with CFRS[], go to susam.net/cfrs.html.