switched index operation from 'a.n' to 'a[n]'

examples/common-array-operations.mq

@@ -1,5 +1,5 @@
 map    := (fn array | result := (), for array (v | result = result & (| fn v) ), result),
-drop   := (n arr | arr.(range n (len arr))),
+drop   := (n arr | arr[range n (len arr)]),
-take   := (n arr | arr.(up n)),
+take   := (n arr | arr[up n]),
-filter := (predicate arr | arr.(map predicate arr)),
+filter := (predicate arr | arr[map predicate arr]),
 

examples/random-rythm.mq

@@ -1,5 +1,5 @@
 for (up 10) (n |
-	snd := c + (shuffle (up 12)).0,
+	snd := c + (pick (up 12)),
 	o := if (n % 2 == 0) 3 4,
 	say snd o,
 	play (oct o, snd qn),

examples/rhythm-of-primes.mq

@@ -36,5 +36,5 @@ oct 3,
 len (1/16),
 
 for (2 + up Length) ( i |
-	play (chord scale.(indicies.(i % primes == 0))),
+	play (chord scale[indicies[i % primes == 0]]),
 ),

musique/errors.hh

@@ -1,10 +1,6 @@
 #ifndef MUSIQUE_ERRORS_HH
 #define MUSIQUE_ERRORS_HH
 
-#if defined(__cpp_lib_source_location)
-#include <source_location>
-#endif
-
 #include <optional>
 #include <system_error>
 #include <variant>

musique/interpreter/builtin_operators.cc

@@ -306,11 +306,11 @@ static constexpr auto Operators = std::array {
 	Operator_Entry { ">",  builtin_operator_compare<std::greater<>> },
 	Operator_Entry { ">=", builtin_operator_compare<std::greater_equal<>> },
 
-	Operator_Entry { ".", builtin_operator_index },
+	Operator_Entry { "[", builtin_operator_index },
 	Operator_Entry { "&", builtin_operator_join },
 };
 
-// All operators should be defined here except 'and' and 'or' which handle evaluation differently
+// All operators should be defined here except '=', 'and' and 'or' which handle evaluation differently
 // and are need unevaluated expressions for their proper evaluation. Exclusion of them is marked
 // as subtraction of total excluded operators from expected constant
 static_assert(Operators.size() == Operators_Count - 3, "All operators handlers are defined here");

musique/lexer/lexer.cc

@@ -90,6 +90,8 @@ auto Lexer::next_token() -> Result<std::variant<Token, End_Of_File>>
 	switch (peek()) {
 	case '(': consume(); return Token { Token::Type::Open_Block,           finish(), token_location };
 	case ')': consume(); return Token { Token::Type::Close_Block,          finish(), token_location };
+	case '[': consume(); return Token { Token::Type::Open_Index,           finish(), token_location };
+	case ']': consume(); return Token { Token::Type::Close_Index,          finish(), token_location };
 	case ',': consume(); return Token { Token::Type::Expression_Separator, finish(), token_location };
 
 	case '|':
@@ -263,6 +265,8 @@ std::ostream& operator<<(std::ostream& os, Token::Type type)
 	case Token::Type::Operator:              return os << "OPERATOR";
 	case Token::Type::Parameter_Separator:   return os << "PARAMETER SEPARATOR";
 	case Token::Type::Symbol:                return os << "SYMBOL";
+	case Token::Type::Open_Index:            return os << "OPEN INDEX";
+	case Token::Type::Close_Index:           return os << "CLOSE INDEX";
 	}
 	unreachable();
 }
@@ -272,10 +276,12 @@ std::string_view type_name(Token::Type type)
 	switch (type) {
 	case Token::Type::Chord:                 return "chord";
 	case Token::Type::Close_Block:           return ")";
+	case Token::Type::Close_Index:           return "]";
 	case Token::Type::Expression_Separator:  return "|";
 	case Token::Type::Keyword:               return "keyword";
 	case Token::Type::Numeric:               return "numeric";
 	case Token::Type::Open_Block:            return "(";
+	case Token::Type::Open_Index:            return "[";
 	case Token::Type::Operator:              return "operator";
 	case Token::Type::Parameter_Separator:   return "parameter separator";
 	case Token::Type::Symbol:                return "symbol";

musique/lexer/token.hh

@@ -13,12 +13,14 @@ struct Token
 		Symbol,               ///< like repeat or choose or chord
 		Keyword,              ///< like true, false, nil
 		Operator,             ///< like "+", "-", "++", "<"
-		Chord,                ///< chord or single note literal, like "c125"
+		Chord,                ///< chord or single note literal, like "c4"
 		Numeric,              ///< numeric literal (floating point or integer)
 		Parameter_Separator,  ///< "|" separaters arguments from block body
-		Expression_Separator, ///< ";" separates expressions. Used mainly to separate calls, like `foo 1 2; bar 3 4`
+		Expression_Separator, ///< "," separates expressions. Used mainly to separate calls, like `foo 1 2; bar 3 4`
-		Open_Block,           ///< "[" delimits anonymous block of code (potentially a function)
+		Open_Block,           ///< "(" starts anonymous block of code (potentially a function)
-		Close_Block,          ///< "]" delimits anonymous block of code (potentially a function)
+		Close_Block,          ///< ")" ends anonymous block of code (potentially a function)
+		Open_Index,           ///< "[" starts index section of index expression
+		Close_Index						///< "]" ends index section of index expression
 	};
 
 	/// Type of token

musique/location.hh

@@ -1,6 +1,10 @@
 #ifndef MUSIQUE_LOCATION_HH
 #define MUSIQUE_LOCATION_HH
 
+#if defined(__cpp_lib_source_location)
+#include <source_location>
+#endif
+
 #include <musique/common.hh>
 #include <ostream>
 

musique/parser/parser.cc

@@ -131,7 +131,6 @@ Result<Ast> Parser::parse_infix_expression()
 		|| expect(Token::Type::Keyword, "or");
 
 	if (next_is_operator) {
-		ensure(not expect(Token::Type::Operator, "."), "This should be handled by parse_index_expression");
 		auto op = consume();
 
 		Ast ast;
@@ -159,7 +158,6 @@ Result<Ast> Parser::parse_rhs_of_infix_expression(Ast lhs)
 		return lhs;
 	}
 
-	ensure(not expect(Token::Type::Operator, "."), "This should be handled by parse_index_expression");
 	auto op = consume();
 
 	if (precedense(lhs.token.source) >= precedense(op.source)) {
@@ -181,18 +179,61 @@ Result<Ast> Parser::parse_rhs_of_infix_expression(Ast lhs)
 	return lhs;
 }
 
+Result<Ast> parse_sequence_inside(
+	Parser &parser,
+	Token::Type closing_token,
+	Location start_location,
+	bool is_lambda,
+	std::vector<Ast> &&parameters,
+	auto &&dont_arrived_at_closing_token
+)
+{
+	auto ast = Try(parser.parse_sequence());
+	if (not parser.expect(closing_token)) {
+		Try(dont_arrived_at_closing_token());
+		return Error {
+			.details = errors::Unexpected_Empty_Source {
+				.reason = errors::Unexpected_Empty_Source::Block_Without_Closing_Bracket,
+				.start = start_location
+			},
+			.location = parser.tokens.back().location
+		};
+	}
+
+	parser.consume();
+
+	if (is_lambda) {
+		return Ast::lambda(start_location, std::move(ast), std::move(parameters));
+	}
+
+	ensure(ast.type == Ast::Type::Sequence, "I dunno if this is a valid assumption tbh");
+	if (ast.arguments.size() == 1) {
+		return std::move(ast.arguments.front());
+	}
+	return Ast::block(start_location, std::move(ast));
+}
+
 Result<Ast> Parser::parse_index_expression()
 {
 	auto result = Try(parse_atomic_expression());
 
-	while (expect(Token::Type::Operator, ".")) {
+	while (expect(Token::Type::Open_Index)) {
 		auto op = consume();
-		if (auto maybe_index = parse_atomic_expression(); maybe_index.has_value()) {
+		auto start_location = op.location;
-			result = Ast::binary(std::move(op), std::move(result), *std::move(maybe_index));
+		result = Ast::binary(
-		} else {
+			std::move(op),
-			// TODO Report that error occured during parsing of index expression
+			std::move(result),
-			return std::move(maybe_index).error();
+			Try(parse_sequence_inside(
+				*this,
+				Token::Type::Close_Index,
+				start_location,
+				false,
+				{},
+				[]() -> std::optional<Error> {
+					return std::nullopt;
 				}
+			))
+		);
 	}
 
 	return result;
@@ -243,12 +284,20 @@ Result<Ast> Parser::parse_atomic_expression()
 				}
 			}
 
-			return parse_sequence().and_then([&](Ast &&ast) -> Result<Ast> {
+			return parse_sequence_inside(
-				if (not expect(Token::Type::Close_Block)) {
+				*this,
-					if (expect(Token::Type::Parameter_Separator)) {
+				Token::Type::Close_Block,
+				opening.location,
+				is_lambda,
+				std::move(parameters),
+				[&]() -> std::optional<Error> {
+					if (!expect(Token::Type::Parameter_Separator)) {
+						return std::nullopt;
+					}
 					if (is_lambda) {
 						ensure(false, "There should be error message that you cannot put multiple parameter separators in one block");
-						} else {
+					}
+
 					// This may be a result of user trying to specify parameters from things that cannot be parameters (like chord literals)
 					// or accidential hit of "|" on the keyboard. We can detect first case by ensuring that all tokens between this place
 					// and beggining of a block are identifier looking: keywords, symbols, literal chord declarations, boolean literals etc
@@ -271,27 +320,9 @@ Result<Ast> Parser::parse_atomic_expression()
 							.location = invalid_token->location
 						};
 					}
+					return std::nullopt;
 				}
-					}
+			);
-					return Error {
-						.details = errors::Unexpected_Empty_Source {
-							.reason = errors::Unexpected_Empty_Source::Block_Without_Closing_Bracket,
-							.start = opening.location
-						},
-						.location = tokens.back().location
-					};
-				}
-				consume();
-				if (is_lambda) {
-					return Ast::lambda(opening.location, std::move(ast), std::move(parameters));
-				} else {
-					ensure(ast.type == Ast::Type::Sequence, "I dunno if this is a valid assumption tbh");
-					if (ast.arguments.size() == 1) {
-						return std::move(ast.arguments.front());
-					}
-					return Ast::block(opening.location, std::move(ast));
-				}
-			});
 		}
 
 	break; case Token::Type::Operator:
@@ -516,7 +547,8 @@ constexpr bool one_of(std::string_view id, auto const& ...args)
 static usize precedense(std::string_view op)
 {
 	// Operators that are not included below are
-	//  '.' since it have own precedense rules and is not binary expression but its own kind of expression
+	//  postfix index operator [] since it have own precedense rules and is not binary expression but its own kind of expression
+	//  in terms of our parsing function hierarchy
 	//
 	//  Exclusion of them is marked by subtracting total number of excluded operators.
 	static_assert(Operators_Count - 1 == 16, "Ensure that all operators have defined precedense below");
@@ -530,9 +562,6 @@ static usize precedense(std::string_view op)
 	if (one_of(op, "*", "/", "%", "&")) return 400;
 	if (one_of(op, "**")) return 500;
 
-
-	std::cerr << op << std::endl;
-
 	unreachable();
 }