Added macros; if is now macro and not a function

examples/factorial.mq

@@ -7,8 +7,8 @@ using Musique programming language
 -- Calculate factorial using recursive approach
 factorial_recursive := (n |
 	if (n <= 1)
-		(| 1)
+		1
-		(| n * (factorial_recursive (n-1)))
+		(n * (factorial_recursive (n-1)))
 );
 
 -- Calculate factorial using iterative approach

examples/fib.mq

@@ -1,5 +1,5 @@
 fib := (n |
 	if (n <= 1)
-		(| n)
+		n
-		(| fib (n-1) + fib (n-2))
+		(fib (n-1) + fib (n-2))
 );

examples/for-elise.mq

@@ -30,7 +30,7 @@ section1 := ( n |
   call subsection1;
 
   if (n == 1)
-    (| sim (a 4 qn) (a 2 e 3 a 3) )
+    ( sim (a 4 qn) (a 2 e 3 a 3) )
     ( sim (a 4 en) (a 2 e 3 a 3)
     ; play (b 4 c 5 d 5)
     )

examples/random-rythm.mq

@@ -1,6 +1,6 @@
 for (up 10) ( n |
 	snd := c + (shuffle (up 12)).0;
-	oct := if (n % 2 == 0) (| 3 ) (| 4 );
+	oct := if (n % 2 == 0) 3 4;
 	say snd oct;
 	play (snd oct qn);
 );

musique/interpreter/builtin_functions.cc

@@ -579,7 +579,7 @@ static Result<Value> builtin_scan(Interpreter &interpreter, std::vector<Value> a
 }
 
 /// Execute blocks depending on condition
-static Result<Value> builtin_if(Interpreter &i, std::vector<Value> args)  {
+static Result<Value> builtin_if(Interpreter &i, std::span<Ast> args)  {
 	static constexpr auto guard = Guard<2> {
 		.name = "if",
 		.possibilities = {
@@ -592,12 +592,10 @@ static Result<Value> builtin_if(Interpreter &i, std::vector<Value> args)  {
 		return guard.yield_error();
 	}
 
-	if (args.front().truthy()) {
+	if (Try(i.eval((Ast)args.front())).truthy()) {
-		auto fun = Try(guard.match<Function>(args[1]));
+		return i.eval((Ast)args[1]);
-		return (*fun)(i, {});
 	} else if (args.size() == 3) {
-		auto fun = Try(guard.match<Function>(args[2]));
+		return i.eval((Ast)args[2]);
-		return (*fun)(i, {});
 	}
 
 	return Value{};

musique/interpreter/interpreter.cc

@@ -167,6 +167,10 @@ Result<Value> Interpreter::eval(Ast &&ast)
 			auto call_location = ast.arguments.front().location;
 			Value func = Try(eval(std::move(ast.arguments.front())));
 
+			if (auto macro = std::get_if<Macro>(&func.data)) {
+				return (*macro)(*this, std::span(ast.arguments).subspan(1));
+			}
+
 			std::vector<Value> values;
 			values.reserve(ast.arguments.size());
 			for (auto& a : std::span(ast.arguments).subspan(1)) {

musique/value/value.hh

@@ -19,6 +19,8 @@ struct Nil
 using Bool   = bool;
 using Symbol = std::string;
 
+using Macro = Result<Value>(*)(Interpreter &i, std::span<Ast>);
+
 /// Representation of any value in language
 struct Value
 {
@@ -52,7 +54,8 @@ struct Value
 		Intrinsic,
 		Block,
 		Array,
-		Chord
+		Chord,
+		Macro
 	> data = Nil{};
 
 	Value();
@@ -71,6 +74,10 @@ struct Value
 	{
 	}
 
+	inline Value(Macro m) : data(m)
+	{
+	}
+
 	/// Returns truth judgment for current type, used primarly for if function
 	bool truthy() const;