Unicode barcode generator in glorious javascript

code39.js

// code39.js -- Unicode barcode generator
// Ported from from Trammell Hudson's original Perl script
// by Johan Persson <jzp@bahnhof.se>
//
// Original header:
// Generate code39 barcodes with unicode characters.
// This doesn't really have a purpose.
// https://trmm.net/Barcode

var patterns = {
    '*': '1 1001',
    'A': '011 10',
    'B': '101 10',
    'C': '001 11',
    'D': '110 10',
    'E': '010 11',
    'F': '100 11',
    'G': '111 00',
    'H': '011 01',
    'I': '101 01',
    'J': '110 01',
    'K': '0111 0',
    'L': '1011 0',
    'M': '0011 1',
    'N': '1101 0',
    'O': '0101 1',
    'P': '1001 1',
    'Q': '1110 0',
    'R': '0110 1',
    'S': '1010 1',
    'T': '1100 1',
    'U': '0 1110',
    'V': '1 0110',
    'W': '0 0111',
    'X': '1 1010',
    'Y': '0 1011',
    'Z': '1 0011',
    '.': '0 1101',
    '-': '1 1100',
    ' ': '1 0101',
    '0': '11 001',
    '1': '01 110',
    '2': '10 110',
    '3': '00 111',
    '4': '11 010',
    '5': '01 011',
    '6': '10 011',
    '7': '11 100',
    '8': '01 101',
    '9': '10 101',
};

var bits = {
    '0' : '█',
    '1': '│',
    ' ': '  ',
};

function code39(str) {
    var last = '';
    return ('*' + str + '*')
        .toUpperCase()
        .split('')
        .map(function (x) {
            return (patterns[x] || patterns[' '])
                .split('')
                .map(function (y) {
                    var padded = (y === '0' && last === '0') ? ' ' + bits[y] : bits[y];
                    last = y;
                    return padded;
                })
                .join('');
        })
        .join('');
}