//title: Interlock Sheet (javascript with knitout module)
// Knit a sheet with alternating rows of back/front and front/back knits; effectively two [[1x1 rib]] sheets interlocked with each-other.

//include knitout module:
const knitout = require('knitout'); //include knitout module
const K = new knitout.Writer({ carriers:['1', '2', '3', '4', '5', '6', '7', '8', '9', '10'] });
K.addHeader('Machine', 'SWGN2');

//Parameters:
let min = 1; //needle number of left edge
let max = 20; //needle number of right edge
let rows = 20; //number of rows to knit
let carrier = "3"; //carrier name

//Because of its structure, interlock does not require a [[cast-on]].
//Instead, we just bring the yarn in and start knitting:
K.inhook(carrier);
K.stitchNumber(105);

// ---- interlock sheet ----
for (let r = 0; r <= rows; r += 1) {
	if (r % 2 === 0) {
		//Even, left-going row:
		for (let n = max; n >= min; n -= 1) {
			if (r === 0 && n === min) {
				//Skip the leftmost stitch in the first row to prevent leftmost column from unravelling:
				continue;
			}
			if ((max - n) % 2 === 0) {
				K.knit("-", 'f' + n, carrier);
			} else {
				K.knit("-", 'b' + n, carrier);
			}
		}
	} else {
		//Odd, right-going row:
		for (let n = min; n <= max; n += 1) {
			if ((max - n) % 2 === 0) {
				K.knit("+", 'b' + n, carrier);
			} else {
				K.knit("+", 'f' + n, carrier);
			}
		}
	}
	
	//The yarn inserting hook can stop holding the yarn tail after two rows have been knit:
	if (r === 1) {
		K.releasehook(carrier);
	}
}

// ---- take carrier out and drop remaining loops ----
//Take carrier out with yarn inserting hook:
K.outhook(carrier);

//drop loops:
for (let n = min; n <= max; n += 1) {
	K.drop('f' + n);
	K.drop('b' + n);
}

K.write('interlock-sheet.swgn2.k');