private static Parser <StepmaniaMeasure> Measure(StepChartType chartType) =>
from rowStrings in Utilities.ListOf(Parse.LetterOrDigit.Many().Text(), Parse.String("\r\n").Or(Parse.String("\n")))
let nonEmptyRows = rowStrings.Where(x => !string.IsNullOrEmpty(x)).ToArray()
let rows = nonEmptyRows.Select((row, rowIndex) => ParseRow(row.Trim(), chartType, rowIndex, nonEmptyRows.Length))
select new StepmaniaMeasure(rows);
private static StepmaniaRow ParseRow(string notes, StepChartType chartType, int rowIndex, int rowCount)
=> new StepmaniaRow(
notes.Select(
(note, noteIndex) =>
new StepmaniaNote(DirectionLookup[chartType][noteIndex], rowCount, (double)rowIndex / rowCount,
StepTypeLookup[note])).Where(x => x.Type != StepType.None));
