parsecsv.js

/*
 * parsecsv.js
 *
 * by: JP 2019
 *
 * example:
 * res = [];
 * if (err = parsecsv('1,2,3\n4,5,6', res))
 *	 console.error(err);
 * // res <-- [["1","2","3"],["4","5","6"]]
 *
 * License MIT
 */
var parsecsv = (function() {
	var ERR_MISSING_QUOTE = 1,
            parstbl = {
	    	ROW: {
	    		'"':     ['QOT', startqot],
	    		',':     ['ROW', pushcol],
	    		'\r':    ['CR',  pushrow],
	    		default: ['COL', startcol]
	    	},
	    	COL: {
	    		',':     ['ROW', pushcol],
	    		'\n':    ['ROW', pushrow],
	    		'\r':    ['CR',  pushrow],
	    		default: ['COL', skipchar]
	    	},
	    	QOT: {
	    		'"':     ['ESC', pushesc],
	    		default: ['QOT', skipchar]
	    	},
	    	ESC: {
	    		'"':     ['QOT', startqot],
	    		'\n':    ['ROW', pushrow],
	    		'\r':    ['CR',  pushrow],
	    		',':     ['ROW', pushcol],
	    		default: ['COL', startcol]
	    	},
	    	CR: {
	    		'\n':    ['ROW', skipchar],
	    		'\r':    ['CR',  pushrow],
	    		',':     ['ROW', pushcol],
	    		'"':     ['QOT', startqot],
	    		default: ['COL', startcol]
	    	},
	    	END: {
	    		default: ['',    pushrow]
	    	}
	    };

	function pushesc() {
		this.col += this.str.slice(this.j, this.i++);
	}

	function pushcol() {
		this.row.push(this.col || this.str.slice(this.j, this.i));
		this.j = ++this.i;
		this.col = '';
	}

	function pushrow() {
		pushcol.call(this);
		this.res.push(this.row);
		this.row = [];
	}

	function skipchar() {
		this.i++;
	}

	function startcol() {
		this.j = this.i++;
	}

	function startqot() {
		this.j = ++this.i;
		this.i = this.str.indexOf('"', this.i);
		if (this.i < 0) {
			this.err = ERR_MISSING_QUOTE;
			this.i = this.str.length;
		}
	}

	return function main(str, res) {
		var action,
		    c,
		    o = {
		    	col: '',
		    	err: 0,
		    	i:   0,
		    	j:   0,
		    	str: str,
		    	res: res,
		    	row: []
		    },
		    state = "ROW",
		    tmp;
		
		while(c = str.charAt(o.i)) {
			tmp    = parstbl[state][c] || parstbl[state].default;
			state  = tmp[0];
			action = tmp[1];
			
			action.call(o);
		}
		
		parstbl.END.default[1].call(o);
		
		return o.err;
	};
})();