grammar.js

module.exports = grammar({
  name: 'rampart',

  rules: {
    // Source files consist of series.
    source_file: $ => seq(
      repeat($._newline),
      repeat($.series),
    ),

    _newline: $ => '\n',

    _record_sep: $ => seq(choice('\n', ',', ',\n'), repeat(' ')),
    _series_sep: $ => seq(choice('\n', '\0', ';', ';\n', ';\0'), repeat(' '), repeat('\n')),

    // Series consist of optional attributes and at least one point and end with at lease one newline.
    series: $ => seq(
      field('attributes', optional($.attribute_list)),
      field('points', $.point_list),
      $._series_sep,
    ),

    // Attributes are a list of '@key value' pairs
    attribute_list: $ => repeat1(seq($.attribute, $._record_sep)),

    // @key value
    // @key "v a l u e"
    attribute: $ => seq(
      '@',
      field('key', $.key),
      repeat1(' '),
      field('value', choice($.value, $.qvalue)),
    ),

    key: $ => $.ustring,
    value: $ => field("content", $.ustring),
    qvalue: $ => seq(
      '"',
      field("content", $.qstring),
      '"',
    ),
    ustring: $ => /[a-zA-Z0-9._-]+/,
    qstring: $ => /[ a-zA-Z0-9._'-]+/,

    // Point lists are lists of time, power points
    point_list: $ => prec.right(seq(repeat(seq($.point, $._record_sep)), $.point, optional($._record_sep))),

    // Times and powers are separated by a space
    point: $ => seq(
      field('time', $._point_time),
      repeat1(' '),
      field('power', $._point_power),
    ),

    // If a time starts with a +, it's a relative time. Otherwise it's absolute.
    _point_time: $ => choice($.abs_time, $.rel_time, $.sus_time),
    abs_time: $ => field('content', $._time),
    rel_time: $ => seq(/\+\s*/, field('content', $._time)),
    sus_time: $ => '_',

    _time: $ => choice($.m, $.hh_mm_ss, $.mm_ss, $.m_ss, $.ss),
    // Plain integers are minutes
    m: $ => /[0-5]?[0-9]/,
    // 15:04:05
    hh_mm_ss: $ => /([01]?[0-9]|2[0-3]):[0-5][0-9]:[0-5][0-9]/,
    // 4:05, 04:05
    m_ss: $ => /[0-5]?[0-9]:[0-5][0-9]/,
    // :04:05
    mm_ss: $ => /:[0-5][0-9]:[0-5][0-9]/,
    // :05
    ss: $ => /:[0-5][0-9]/,

    // If a power starts with a +, it's a relative power. Otherwise it's absolute.
    // If a _ is given instead of a power, the previous power is sustained.
    _point_power: $ => choice($.abs_power, $.rel_power, $.sus_power),
    abs_power: $ => field('content', $._power),
    rel_power: $ => seq(/\+\s*/, field('content', $._power)),
    sus_power: $ => '_',

    _power: $ => choice($.integer, $.decimal, $.exponent),
    // 123
    integer: $ => /-?\d(_?\d)*/,
    // 123.456
    decimal: $ => /-?(\d(_?\d)*)?\.(_?\d)*/,
    // 1.23456e2
    exponent: $ => /-?(\d(_?\d)*)?(\.(_?\d)*)?[eE]-?\d(_?\d)*/,

    comment: $ => /\s*\/\/.*/,
  },

  // Comments are ignored
  extras: $ => [$.comment],
});