function parse(text) {
    // https://github.com/shioyadan/Konata/blob/master/docs/kanata-log-format.md

    const before = performance.now();

    let line_start = 0;
    let line_index = 0;

    //console.log(text);

    for (let i = 0; i < text.length; ++i) {
        const c = text[i];
    
        if (c === '\n') {
            // TODO: speed
            const line_copy = text.substring(line_start, i);
            const line_parts = line_copy.split(/\s+/);

            if (line_parts.length === 0) {
                console.error('Parser error: empty line');
                return false;
            }

            const command = line_parts[0];
            switch (command) {
                case 'Kanata': {
                    if (!assert_arglen(line_parts, 1, 'Kanata')) return false;

                    const version = Number(line_parts[1]);
                    if (version !== 4) {
                        console.error('Parser error: only Kanata traces version 4 are supported');
                        return false;
                    }

                    break;
                }

                case 'C=': {
                    if (!assert_arglen(line_parts, 1, 'C=')) return false;

                    const cycles = Number(line_parts[1]);

                    break;
                }

                case 'C': {
                    if (!assert_arglen(line_parts, 1, 'C')) return false;

                    const cycles = Number(line_parts[1]);

                    break;
                }

                case 'I': {
                    if (!assert_arglen(line_parts, 3, 'I')) return false;

                    const insn_id_in_file = Number(line_parts[1]);
                    const insn_id_in_sim = Number(line_parts[2]);
                    const thread_id = Number(line_parts[3]);

                    break;
                }

                case 'L': {
                    if (!assert_arglenmin(line_parts, 3, 'L')) return false;

                    const id = Number(line_parts[1]);
                    const type = Number(line_parts[2]);
                    const text = line_parts.slice(3).join(' '); // TODO: preserve spacing, newlines

                    break;
                }

                case 'S': {
                    if (!assert_arglen(line_parts, 3, 'S')) return false;

                    const id = Number(line_parts[1]);
                    const lane = Number(line_parts[2]);
                    const stage = line_parts[3];

                    break;
                }

                case 'E': {
                    if (!assert_arglen(line_parts, 3, 'E')) return false;

                    const id = Number(line_parts[1]);
                    const lane = Number(line_parts[2]);
                    const stage = line_parts[3];

                    break;
                }

                case 'R': {
                    if (!assert_arglen(line_parts, 3, 'R')) return false;

                    const id = Number(line_parts[1]);
                    const retire_id = Number(line_parts[2]);
                    const type = Number(line_parts[3]);

                    break;
                }

                case 'W': {
                    if (!assert_arglen(line_parts, 3, 'W')) return false;

                    const consumer_id = Number(line_parts[1]);
                    const producer_id = Number(line_parts[2]);
                    const type = Number(line_parts[3]);

                    break;
                }

                default: {
                    console.error('Parser error: unexpected command', command);
                    return false;
                }
            }
            //console.log(command);

            line_start = i + 1;
            line_index += 1;
        }
    }

    const after = performance.now();

    console.log(`Parsed in ${Math.round(after - before)}ms`);
}

function assert_arglen(args, arglen, command) {
    if (args.length !== arglen + 1) {
        console.error(`Parser error: command ${command} requires ${arglen} argument(s)`);
        return false;
    }

    return true;
}

function assert_arglenmin(args, arglen, command) {
    if (args.length < arglen + 1) {
        console.error(`Parser error: command ${command} requires at least ${arglen} argument(s)`);
        return false;
    }

    return true;
}