Moanfuck implementation in js

mfck.js

// moanfuck implementation in JavaScript
// Use as: interpret(<mf code>)
// or: interpret(convert(<bf code>)) if you want to try using bf code.
// logs to the console.

// borrowed from https://github.com/trekhleb/javascript-algorithms/blob/master/src/algorithms/string/levenshtein-distance/levenshteinDistance.js
function levenshteinDistance(a, b) {
	// Create empty edit distance matrix for all possible modifications of
	// substrings of a to substrings of b.
	const distanceMatrix = Array(b.length + 1).fill(null).map(() => Array(a.length + 1).fill(null));

	// Fill the first row of the matrix.
	// If this is first row then we're transforming empty string to a.
	// In this case the number of transformations equals to size of a substring.
	for (let i = 0; i <= a.length; i += 1) {
		distanceMatrix[0][i] = i;
	}

	// Fill the first column of the matrix.
	// If this is first column then we're transforming empty string to b.
	// In this case the number of transformations equals to size of b substring.
	for (let j = 0; j <= b.length; j += 1) {
		distanceMatrix[j][0] = j;
	}

	for (let j = 1; j <= b.length; j += 1) {
		for (let i = 1; i <= a.length; i += 1) {
			const indicator = a[i - 1] === b[j - 1] ? 0 : 1;
			distanceMatrix[j][i] = Math.min(
				distanceMatrix[j][i - 1] + 1, // deletion
				distanceMatrix[j - 1][i] + 1, // insertion
				distanceMatrix[j - 1][i - 1] + indicator, // substitution
			);
		}
	}

	return distanceMatrix[b.length][a.length];
}

// 0 + AH
// 1 - OH
// 2 > YES
// 3 < FUCK
// 4 , MORE
// 5 . YEAH
// 6 [ AHH
// 7 ] OOH
// 8 # BABY (debug breakpoint)

function interpret(code, input) {
	var instructions = ["AH", "OH", "YES", "FUCK", "MORE", "YEAH", "AHH", "OOH", "BABY"];
	var cell = 0;
	var output = "";
	var inputpos = 0;
	var data = [];
	var loop = [];
	var next = 0;
	var closest = function (a) {
		var dist = instructions.map(x => levenshteinDistance(x, a));
		return dist.indexOf(Math.min(...dist));
	};
	var fCode = code.toUpperCase().split(" ").map(x => closest(x))

	while (next < fCode.length) {
		switch (fCode[next]) {
			case 0:
				if (~loop[0]) {
					data[cell] = (data[cell] || 0) + 1;
				}
				break;
			case 1:
				if (~loop[0]) {
					data[cell] = (data[cell] || 0) - 1;
				}
				break;
			case 2:
				if (~loop[0]) {
					cell++;
				}
				break;
			case 3:
				if (~loop[0]) {
					cell--;
				}
				break;
			case 4:
				if (~loop[0]) {
					data[cell] = input.charCodeAt(inputpos);
					inputpos++;
				}
				break;
			case 5:
				if (~loop[0]) {
					output = output + String.fromCharCode(data[cell]);
				}
				break;
			case 6:
				loop.unshift(data[cell] ? next : -1);
				break;
			case 7:
				if (~loop[0] && data[cell]) {
					next = loop[0];
				} else {
					loop.shift();
				}
				break;
			case 8:
				console.log("Current state:", data)
				break;
			default:
				console.log("idk what the hell you did but you got this message");
		}
		next++;
	}
	console.log(output)
}

function convert(code) {
	var instructions = ["AH", "OH", "YES", "FUCK", "MORE", "YEAH", "AHH", "OOH", "BABY"];

	var bf = "+-><,.[]#";
	var c = code.split('');
	var newC = c.map(x => instructions[bf.indexOf(x)]).join(" ");
  console.log(newC);
  return newC;
}