Chords!

src/interpreter.cc

@@ -113,7 +113,7 @@ Interpreter::Interpreter()
 		global.force_define("play", +[](Interpreter &i, std::vector<Value> args) -> Result<Value> {
 			for (auto &arg : args) {
 				assert(arg.type == Value::Type::Music, "Only music values can be played"); // TODO(assert)
-				i.play(arg.note);
+				i.play(arg.chord);
 			}
 			return Value{};
 		});
@@ -264,16 +264,31 @@ void Interpreter::leave_scope()
 	env = env->leave();
 }
 
-void Interpreter::play(Note note)
+void Interpreter::play(Chord chord)
 {
 	assert(midi_connection, "To play midi Interpreter requires instance of MIDI connection");
 
 	auto &ctx = context_stack.back();
-	note = ctx.fill(std::move(note));
 
-	auto dur = ctx.length_to_duration(note.length);
+	// Fill all notes that don't have octave or length with defaults
+	std::transform(chord.notes.begin(), chord.notes.end(), chord.notes.begin(), [&](Note note) { return ctx.fill(note); });
 
-	midi_connection->send_note_on(0, *note.into_midi_note(), 127);
-	std::this_thread::sleep_for(dur);
-	midi_connection->send_note_off(0, *note.into_midi_note(), 127);
+	// Sort that we have smaller times first
+	std::sort(chord.notes.begin(), chord.notes.end(), [](Note const& lhs, Note const& rhs) { return lhs.length < rhs.length; });
+
+	Number max_time = *chord.notes.back().length;
+
+	// Turn all notes on
+	for (auto const& note : chord.notes) {
+		midi_connection->send_note_on(0, *note.into_midi_note(), 127);
+	}
+
+	// Turn off each note at right time
+	for (auto const& note : chord.notes) {
+		if (max_time != Number(0)) {
+			max_time -= *note.length;
+			std::this_thread::sleep_for(ctx.length_to_duration(*note.length));
+		}
+		midi_connection->send_note_off(0, *note.into_midi_note(), 127);
+	}
 }

src/lexer.cc

@@ -105,12 +105,7 @@ auto Lexer::next_token() -> Result<Token>
 		// Allow `c#`
 		consume_if('#');
 
-		// Any of the following sequences are allowed
-		// c,,,,,,,,,,,,,,,,
-		// c1,,,,2,3212
-		// c1234'''''
-		// during lexing
-		while (consume_if(",'") || consume_if(unicode::is_digit)) {}
+		while (consume_if('_') || consume_if(unicode::is_digit)) {}
 
 		// If we encounter any letter that is not part of chord declaration,
 		// then we have symbol, not chord declaration
@@ -125,9 +120,7 @@ auto Lexer::next_token() -> Result<Token>
 	if (consume_if(std::bind(unicode::is_identifier, _1, unicode::First_Character::Yes))) {
 	symbol_lexing:
 		for (auto predicate = std::bind(unicode::is_identifier, _1, unicode::First_Character::No);
-				consume_if(predicate);
-		) {
-		}
+				consume_if(predicate);) {}
 
 		Token t = { Token::Type::Symbol, finish(), token_location };
 		if (std::find(Keywords.begin(), Keywords.end(), t.source) != Keywords.end()) {

src/musique.hh

@@ -494,6 +494,17 @@ struct Note
 
 std::ostream& operator<<(std::ostream& os, Note const& note);
 
+struct Chord
+{
+	std::vector<Note> notes;
+
+	static Chord from(std::string_view source);
+
+	bool operator==(Chord const&) const = default;
+};
+
+std::ostream& operator<<(std::ostream& os, Chord const& chord);
+
 /// Eager Array
 struct Array
 {
@@ -523,6 +534,7 @@ struct Value
 	static Value from(Block &&l);
 	static Value from(Array &&array);
 	static Value from(Note n);
+	static Value from(Chord chord);
 
 	enum class Type
 	{
@@ -533,7 +545,7 @@ struct Value
 		Intrinsic,
 		Block,
 		Array,
-		Music
+		Music,
 	};
 
 	Value() = default;
@@ -551,7 +563,7 @@ struct Value
 	Number n;
 	Intrinsic intr;
 	Block blk;
-	Note note;
+	Chord chord;
 	Array array;
 
 	// TODO Most strings should not be allocated by Value, but reference to string allocated previously
@@ -647,7 +659,7 @@ struct Interpreter
 	void leave_scope();
 
 	/// Play note resolving any missing parameters with context via `midi_connection` member.
-	void play(Note n);
+	void play(Chord);
 };
 
 namespace errors

src/value.cc

@@ -83,7 +83,7 @@ Result<Value> Value::from(Token t)
 			return Value::from(*maybe_note);
 		}
 
-		unimplemented("only simple note values (like c or e#) are supported now");
+		return Value::from(Chord::from(t.source));
 
 	default:
 		unimplemented();
@@ -150,7 +150,15 @@ Value Value::from(Note n)
 {
 	Value v;
 	v.type = Type::Music;
-	v.note = n;
+	v.chord = { .notes = { n } };
+	return v;
+}
+
+Value Value::from(Chord chord)
+{
+	Value v;
+	v.type = Type::Music;
+	v.chord = std::move(chord);
 	return v;
 }
 
@@ -164,11 +172,12 @@ Result<Value> Value::operator()(Interpreter &i, std::vector<Value> args)
 			assert(args.size() == 1 || args.size() == 2, "music value can be called only in form note <octave> [<length>]"); // TODO(assert)
 			assert(args[0].type == Type::Number, "expected octave to be a number"); // TODO(assert)
 
-			note.octave = args[0].n.as_int();
-
-			if (args.size() == 2) {
-				assert(args[1].type == Type::Number, "expected length to be a number"); // TODO(assert)
-				note.length = args[1].n;
+			assert(args.size() == 2 ? args[1].type == Type::Number : true, "expected length to be a number"); // TODO(assert)
+			for (auto &note : chord.notes) {
+				note.octave = args[0].n.as_int();
+				if (args.size() == 2) {
+					note.length = args[1].n;
+				}
 			}
 
 			return *this;
@@ -224,7 +233,7 @@ bool Value::operator==(Value const& other) const
 	case Type::Intrinsic: return intr == other.intr;
 	case Type::Block:     return false; // TODO Reconsider if functions are comparable
 	case Type::Bool:      return b == other.b;
-	case Type::Music:     return note == other.note;
+	case Type::Music:     return chord == other.chord;
 	case Type::Array:     return array == other.array;
 	}
 
@@ -272,7 +281,7 @@ std::ostream& operator<<(std::ostream& os, Value const& v)
 		return os << v.array;
 
 	case Value::Type::Music:
-		return os << v.note;
+		return os << v.chord;
 	}
 	unreachable();
 }
@@ -374,18 +383,13 @@ u8 Note::into_midi_note(i8 default_octave) const
 std::ostream& operator<<(std::ostream& os, Note const& note)
 {
 	os << note_index_to_string(note.base);
-	os << ":oct=";
 	if (note.octave) {
-		os << int(*note.octave);
-	} else {
-		os << '_';
+		os << ":oct=" << int(*note.octave);
 	}
-	os << ":len=";
 	if (note.length) {
-		os << *note.length;
-	} else {
-		os << '_';
+		os << ":len=" << *note.length;
 	}
+
 	return os;
 }
 
@@ -393,3 +397,32 @@ bool Note::operator==(Note const& other) const
 {
 	return octave == other.octave && base == other.base && length == other.length;
 }
+
+Chord Chord::from(std::string_view source)
+{
+	auto note = Note::from(source);
+	assert(note.has_value(), "don't know how this could happen");
+
+	Chord chord;
+	source.remove_prefix(1 + (source[1] == '#'));
+	chord.notes.push_back(*std::move(note));
+
+	for (char digit : source) {
+		chord.notes.push_back(Note { .base = u8(digit - '0') });
+	}
+
+	return chord;
+}
+
+std::ostream& operator<<(std::ostream& os, Chord const& chord)
+{
+	os << "chord[";
+
+	for (auto it = chord.notes.begin(); it != chord.notes.end(); ++it) {
+		os << *it;
+		if (std::next(it) != chord.notes.end())
+			os << "; ";
+	}
+
+	return os << ']';
+}