check if block is a collection at runtime; operators pretty printing

CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - new builtins: map, while, set_len, duration
 - `<note><octave>` notation like `c4` that mimics [scientific notation](https://en.wikipedia.org/wiki/Scientific_pitch_notation)
+- operator pretty printing while printing values
 
 ### Changed
 
@@ -22,6 +23,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - Index operation using booleans behaves like a mask and not fancy way of spelling 0 and 1
+- Blocks are check against beeing a collection at runtime to prevent treating anonymous functions as collections and cousing assertions
 
 ### Removed
 

musique/accessors.hh

@@ -1,34 +1,44 @@
 #ifndef MUSIQUE_ACCESSORS_HH
 #define MUSIQUE_ACCESSORS_HH
 
+#include <musique/common.hh>
 #include <musique/errors.hh>
 #include <variant>
+#include <iostream>
+#include <musique/value/collection.hh>
 
-template<typename Desired, typename ...V>
-constexpr Desired* get_if(std::variant<V...> &v)
+namespace details
 {
-	return std::visit([]<typename Actual>(Actual &act) -> Desired* {
-		if constexpr (std::is_same_v<Desired, Actual>) {
-			return &act;
-		} else if constexpr (std::is_base_of_v<Desired, Actual>) {
-			return static_cast<Desired*>(&act);
-		} else {
-			return nullptr;
-		}
-	}, v);
+	template<typename T>
+	concept Reference = std::is_lvalue_reference_v<T>;
 }
 
-template<typename Desired, typename ...V>
-constexpr Desired const* get_if(std::variant<V...> const& v)
+template<typename Desired, same_template_as<std::variant> Variant>
+requires details::Reference<Variant>
+constexpr auto get_if(Variant &&v)
 {
-	return std::visit([]<typename Actual>(Actual const& act) -> Desired const* {
-		if constexpr (std::is_same_v<Desired, Actual>) {
+	using Return_Type = std::conditional_t<
+		std::is_const_v<std::remove_reference_t<Variant>>,
+		Desired const*,
+		Desired*
+	>;
+
+	return std::visit([]<details::Reference Actual>(Actual&& act) -> Return_Type {
+		if constexpr (std::is_same_v<Desired, std::remove_cvref_t<Actual>>) {
 			return &act;
-		} else if constexpr (std::is_base_of_v<Desired, Actual>) {
-			return static_cast<Desired const*>(&act);
+		} else if constexpr (std::is_base_of_v<Desired, std::remove_cvref_t<Actual>>) {
+			auto ret = static_cast<Return_Type>(&act);
+			if constexpr (std::is_same_v<std::remove_cvref_t<Desired>, Collection>) {
+				if (ret->is_collection()) {
+					return ret;
 				} else {
 					return nullptr;
 				}
+			} else {
+				return ret;
+			}
+		}
+		return nullptr;
 	}, v);
 }
 
@@ -39,31 +49,5 @@ constexpr Desired& get_ref(std::variant<V...> &v)
 	unreachable();
 }
 
-#if 0
-template<typename ...T, typename Values>
-constexpr auto match(Values& values) -> std::optional<std::tuple<T...>>
-{
-	return [&]<std::size_t ...I>(std::index_sequence<I...>) -> std::optional<std::tuple<T...>> {
-		if (sizeof...(T) == values.size() && (std::holds_alternative<T>(values[I].data) && ...)) {
-			return {{ std::get<T>(values[I].data)... }};
-		} else {
-			return std::nullopt;
-		}
-	} (std::make_index_sequence<sizeof...(T)>{});
-}
-
-template<typename ...T, typename Values>
-constexpr auto match_ref(Values& values) -> std::optional<std::tuple<T&...>>
-{
-	return [&]<std::size_t ...I>(std::index_sequence<I...>) -> std::optional<std::tuple<T&...>> {
-		if (sizeof...(T) == values.size() && (get_if<T>(values[I].data) && ...)) {
-			return {{ get_ref<T>(values[I].data)... }};
-		} else {
-			return std::nullopt;
-		}
-	} (std::make_index_sequence<sizeof...(T)>{});
-}
-#endif
-
 #endif
 

musique/common.hh

@@ -38,6 +38,9 @@ struct is_template<Template, Template<T...>> : std::true_type {};
 template<template<typename ...> typename Template, typename T>
 constexpr auto is_template_v = is_template<Template, T>::value;
 
+template<typename T, template<typename ...> typename Template>
+concept same_template_as = is_template_v<Template, std::remove_cvref_t<T>>;
+
 /// Drop in replacement for bool when C++ impilcit conversions stand in your way
 struct Explicit_Bool
 {

musique/format.cc

@@ -3,6 +3,7 @@
 #include <musique/format.hh>
 #include <musique/try.hh>
 #include <musique/value/value.hh>
+#include <musique/interpreter/interpreter.hh>
 
 Result<std::string> format(Interpreter &i, Value const& value)
 {
@@ -21,11 +22,17 @@ std::optional<Error> Value_Formatter::format(std::ostream& os, Interpreter &inte
 	return std::visit(Overloaded {
 		[&](Intrinsic const& intrinsic) -> std::optional<Error> {
 			for (auto const& [key, val] : Env::global->variables) {
-				if (auto other = get_if<Intrinsic>(val); intrinsic == *other) {
+				if (auto other = get_if<Intrinsic>(val); other && intrinsic == *other) {
 					os << "<intrinsic '" << key << "'>";
 					return {};
 				}
 			}
+			for (auto const& [key, val] : interpreter.operators) {
+				if (intrinsic == val) {
+					os << "<operator '" << key << "'>";
+					return {};
+				}
+			}
 			os << "<intrinsic>";
 			return {};
 		},
@@ -41,6 +48,7 @@ std::optional<Error> Value_Formatter::format(std::ostream& os, Interpreter &inte
 			return {};
 		},
 		[&](Block const& block) -> std::optional<Error> {
+			if (block.is_collection()) {
 				os << '(';
 				for (auto i = 0u; i < block.size(); ++i) {
 					if (i > 0) {
@@ -49,6 +57,9 @@ std::optional<Error> Value_Formatter::format(std::ostream& os, Interpreter &inte
 					Try(nest(Inside_Block).format(os, interpreter, Try(block.index(interpreter, i))));
 				}
 				os << ')';
+			} else {
+				os << "<block>";
+			}
 			return {};
 		},
 		[&](auto&&) -> std::optional<Error> {

musique/interpreter/builtin_functions.cc

@@ -549,10 +549,9 @@ static Result<Value> builtin_fold(Interpreter &interpreter, std::vector<Value> a
 static Result<Value> builtin_map(Interpreter &interpreter, std::vector<Value> args)
 {
 	static constexpr auto guard = Guard<2> {
-		.name = "fold",
+		.name = "map",
 		.possibilities = {
-			"(callback, array) -> any",
-			"(callback, array, init) -> any"
+			"(callback, array) -> any"
 		}
 	};
 

musique/value/array.cc

@@ -38,3 +38,8 @@ std::ostream& operator<<(std::ostream& os, Array const& v)
 	}
 	return os << ')';
 }
+
+bool Array::is_collection() const
+{
+	return true;
+}

musique/value/array.hh

@@ -32,6 +32,8 @@ struct Array : Collection
 	/// Arrays are equal if all of their elements are equal
 	bool operator==(Array const&) const = default;
 
+	bool is_collection() const override;
+
 	/// Print array
 	friend std::ostream& operator<<(std::ostream& os, Array const& v);
 };

musique/value/block.cc

@@ -16,7 +16,7 @@ static inline std::optional<Error> guard_index(unsigned index, unsigned size)
 // TODO Add memoization
 Result<Value> Block::index(Interpreter &i, unsigned position) const
 {
-	ensure(parameters.size() == 0, "cannot index into block with parameters (for now)");
+	ensure(parameters.empty(), "cannot index into block with parameters (for now)");
 	if (body.type != Ast::Type::Sequence) {
 		Try(guard_index(position, 1));
 		return i.eval((Ast)body);
@@ -57,3 +57,8 @@ Result<Value> Block::operator()(Interpreter &i, std::vector<Value> arguments) co
 	i.env = old_scope;
 	return result;
 }
+
+bool Block::is_collection() const
+{
+	return parameters.empty();
+}

musique/value/block.hh

@@ -36,6 +36,8 @@ struct Block : Collection, Function
 
 	/// Count of elements in block
 	usize size() const override;
+
+	bool is_collection() const override;
 };
 
 #endif

musique/value/collection.hh

@@ -17,6 +17,8 @@ struct Collection
 	/// Return elements count
 	virtual usize size() const = 0;
 
+	virtual bool is_collection() const = 0;
+
 	bool operator==(Collection const&) const = default;
 };