#!/usr/local/bin/ised --f
@0{1 3 0 3 1};  #! A to B-A-B
@1{0 2 1 2 0};  #! B to A+B+A
@2{2};          #! + to +
@3{3};          #! - to -
@10{$$$$$$$$0}; #! 8 iterations of the system, starting with A ($0)

#! $10 is already the result we wanted.
#! However, to draw the curve, we must simulate turtle graphics
@11{ {0 0 1 -1}_$10 };   #! A and B mean forward, + means left (1=90 degrees), - means right (-1=-90 degrees)
@12(0 $11 -1);           #! cumulative of angle changes gives absolute orientations
#! now directions [0 5] (plus any integer multiple of 6) represent 6 directions in space
#! cumulative x and y coordinates
@13(0 {1 0.5 -0.5 -1 -0.5 0.5}_$12 -1);         #! note the x components of hexagon
@14(0 {0 sqt3/2*{1 1} 0 -sqt3/2*{1 1}}_$12 -1); #! note the y components of hexagon
--t '$13;$14'