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function startswith(a, b) {
for(let i=0; i<b.length; i++) {
// in JS, ['X'] == 'X'
if((a[i] != b[i]) | (typeof a[i] != typeof b[i])) {
return false;
}
}
return true;
}
function generate(start, rules, iterations) {
if(iterations == 0) {
return start;
}
for(let rule of rules) {
let pos = 0;
while(pos < start.length) {
let w = start.slice(pos, pos + rule[0].length);
if(startswith(w, rule[0])) {
start.splice(pos, rule[0].length, rule[1])
pos += rule[0].length;
} else {
pos += 1;
}
}
}
// TODO find a better way
let ret = [];
for(let x of start) {
if(typeof x === 'object') {
// TODO why?
//ret.concat(x);
ret = ret.concat(x);
} else {
ret.push(x);
}
}
return generate(ret, rules, iterations - 1);
}
function draw_initstate(p, state) {
if(!('dir' in state)) {
state.dir = 0;
}
if(!('curpath' in state)) {
p.addChild(new paper.Path());
state.curpath = p.lastChild;
}
}
function draw_set_dir(dir) {
return function(p, state) {
state.dir = dir;
}
}
function draw_forward() {
return function(p, state) {
draw_initstate(p, state);
if(state.curpath.segments.length == 0) {
state.curpath.add(new paper.Point(0, 0));
console.log('---------------------------');
}
var lastp = state.curpath.segments[state.curpath.segments.length - 1].point;
state.curpath.add(lastp.add(
new paper.Point(Math.sin(state.dir), Math.cos(state.dir))
));
}
}
function draw_turn(angle) {
return function(p, state) {
draw_initstate(p, state);
state.dir += angle;
}
}
function draw_angle_turn(fac) {
return function(p, state) {
draw_initstate(p, state);
state.dir += state.angle * fac;
}
}
function draw_angle_init(angle) {
return function(p, state) {
state.angle = angle;
}
}
function draw_angle_add(delta) {
return function(p, state) {
state.angle += delta;
}
}
function draw_state_push() {
return function(p, state) {
if(typeof state.stack == 'undefined') {
state.stack = new Array();
}
state.stack.push({
pos: state.curpath.segments[state.curpath.segments.length - 1].point,
dir: state.dir,
});
}
}
function draw_state_pop() {
return function(p, state) {
var s = state.stack.pop();
state.dir = s.dir;
p.addChild(new paper.Path());
state.curpath = p.lastChild;
state.curpath.add(s.pos);
}
}
function draw(word, actions) {
var p = new paper.CompoundPath();
var state = {};
for(let w of word) {
if(w in actions) {
actions[w](p, state);
}
}
return p;
}