CSV RFC 4180 parser

csv2arr.js

/*
 * CSV parser
 * 
 * See RFC 4180 for CSV format specification.
 * 
 * License MIT
 * JP2019
 */

/**
 * "1,2,3\n4,5,6" -> [["1", "2", "3"], ["4", "5", "6"]]
 * @param {string} csv - csv formatted string
 * @param {Array} res - array for result
 * @param {string} delimiter - optional, defaults to ','
 * @return {number} error code
 */
function csv2arr(csv, res, delimiter) {
    delimiter = delimiter || ',';
    var ERR_MISSING_QUOTE = 1, /* no enclosing quote */
	i = 0, /* current index */
	j, /* cell start index */
        c,
        row = [],
        col = '',
        I,
        N = csv.length;
    if (csv.charCodeAt(N-1) === 10) N--;
    if (csv.charCodeAt(N-1) === 13) N--;

    col:
    while (true) {
        if (csv.charCodeAt(i) === 34) {
            j = ++i;
			i = csv.indexOf('"', j);
            if (i < 0) {
                //err = ERR_MISSING_QUOTE;
                i = N;
            }
			col += csv.slice(j, i++);
			while((c=csv.charCodeAt(i)) === 34) {
				j = i++;
				i = csv.indexOf('"', i);
				if (i < 0) {
                    //err = ERR_MISSING_QUOTE;
                    i = N;
                }
				col += csv.slice(j, i++);
            }
            row.push(col);
            col='';
            switch(c) {
            case 13:
                if (csv.charCodeAt(i+1) === 10) ++i;
            case 10:
                res.push(row);
                row = [];
            }
            i++;
            continue;
        }

        j = i;
        while(i < N) {
            switch(csv.charCodeAt(I = i)) {
            case 13:
                if (csv.charCodeAt(i+1) === 10) ++i;
            case 10:
                row.push(csv.slice(j, I))
                res.push(row);
                row = [];
                i++;
                continue col;
            case 44:
                row.push(csv.slice(j, I));
                i++;
                continue col;
            }
            i++;
        }
        row.push(col || csv.slice(j, i));
        res.push(row);
        return 0;
    }
}