Eval: Change (macroexpand) into (macroexpand-1)

src/eval-special-form.cpp

@@ -88,12 +88,7 @@ ValuePtr Eval::evalFn(const ValueVector& nodes, EnvironmentPtr env)
 	return makePtr<Lambda>(bindings, *std::next(nodes.begin()), env);
 }
 
-ValuePtr Eval::evalMacroExpand(const ValueVector& nodes, EnvironmentPtr env)
-{
-	CHECK_ARG_COUNT_IS("macroexpand", nodes.size(), 1);
-
-	return macroExpand(nodes.front(), env);
-}
+// -----------------------------------------
 
 // (quasiquoteexpand x)
 ValuePtr Eval::evalQuasiQuoteExpand(const ValueVector& nodes)
@@ -237,6 +232,53 @@ void Eval::evalLet(const ValueVector& nodes, EnvironmentPtr env)
 
 // -----------------------------------------
 
+// (x y z)
+static bool isMacroCall(ValuePtr ast, EnvironmentPtr env)
+{
+	auto list = dynamic_cast<List*>(ast.get());
+
+	if (list == nullptr || list->empty()) {
+		return false;
+	}
+
+	auto front = list->front().get();
+
+	if (!is<Symbol>(front)) {
+		return false;
+	}
+
+	auto symbol = dynamic_cast<Symbol*>(front)->symbol();
+	auto value = env->get(symbol).get();
+
+	if (!is<Macro>(value)) {
+		return false;
+	}
+
+	return true;
+}
+
+void Eval::evalMacroExpand1(const ValueVector& nodes, EnvironmentPtr env)
+{
+	CHECK_ARG_COUNT_IS("macroexpand-1", nodes.size(), 1, void());
+
+	if (!isMacroCall(nodes.front(), env)) {
+		m_ast = nodes.front();
+		m_env = env;
+		return;
+	}
+
+	auto list = std::static_pointer_cast<List>(nodes.front());
+
+	auto value = env->get(std::static_pointer_cast<Symbol>(list->front())->symbol());
+	auto lambda = std::static_pointer_cast<Lambda>(value);
+
+	m_ast = lambda->body();
+	m_env = Environment::create(lambda, list->rest());
+	return; // TCO
+}
+
+// -----------------------------------------
+
 static bool isSymbol(ValuePtr value, const std::string& symbol)
 {
 	if (!is<Symbol>(value.get())) {
@@ -331,6 +373,8 @@ void Eval::evalQuasiQuote(const ValueVector& nodes, EnvironmentPtr env)
 	return; // TCO
 }
 
+// -----------------------------------------
+
 // (while true body...)
 void Eval::evalWhile(const ValueVector& nodes, EnvironmentPtr env)
 {

src/eval.cpp

@@ -83,9 +83,6 @@ ValuePtr Eval::evalImpl()
 			if (symbol == "fn*") {
 				return evalFn(nodes, env);
 			}
-			if (symbol == "macroexpand") {
-				return evalMacroExpand(nodes, env);
-			}
 			if (symbol == "quasiquoteexpand") {
 				return evalQuasiQuoteExpand(nodes);
 			}
@@ -108,6 +105,10 @@ ValuePtr Eval::evalImpl()
 				evalLet(nodes, env);
 				continue; // TCO
 			}
+			if (symbol == "macroexpand-1") {
+				evalMacroExpand1(nodes, env);
+				continue; // TCO
+			}
 			if (symbol == "quasiquote") {
 				evalQuasiQuote(nodes, env);
 				continue; // TCO
@@ -202,50 +203,6 @@ ValuePtr Eval::evalHashMap(ValuePtr ast, EnvironmentPtr env)
 
 // -----------------------------------------
 
-// (x y z)
-bool Eval::isMacroCall(ValuePtr ast, EnvironmentPtr env)
-{
-	auto list = dynamic_cast<List*>(ast.get());
-
-	if (list == nullptr || list->empty()) {
-		return false;
-	}
-
-	auto front = list->front().get();
-
-	if (!is<Symbol>(front)) {
-		return false;
-	}
-
-	auto symbol = dynamic_cast<Symbol*>(front)->symbol();
-	auto value = env->get(symbol).get();
-
-	if (!is<Macro>(value)) {
-		return false;
-	}
-
-	return true;
-}
-
-// (x y z)
-ValuePtr Eval::macroExpand(ValuePtr ast, EnvironmentPtr env)
-{
-	while (isMacroCall(ast, env)) {
-		auto list = std::static_pointer_cast<List>(ast);
-
-		auto value = env->get(std::static_pointer_cast<Symbol>(list->front())->symbol());
-		auto lambda = std::static_pointer_cast<Lambda>(value);
-
-		m_ast = lambda->body();
-		m_env = Environment::create(lambda, list->rest());
-		ast = evalImpl();
-	}
-
-	return ast;
-}
-
-// -----------------------------------------
-
 ValuePtr Eval::apply(ValuePtr function, const ValueVector& nodes)
 {
 	if (!is<Function>(function.get())) {

src/eval.h

@@ -31,13 +31,9 @@ private:
 	ValuePtr evalVector(ValuePtr ast, EnvironmentPtr env);
 	ValuePtr evalHashMap(ValuePtr ast, EnvironmentPtr env);
 
-	bool isMacroCall(ValuePtr ast, EnvironmentPtr env);
-	ValuePtr macroExpand(ValuePtr ast, EnvironmentPtr env);
-
 	ValuePtr evalDef(const ValueVector& nodes, EnvironmentPtr env);
 	ValuePtr evalDefMacro(const ValueVector& nodes, EnvironmentPtr env);
 	ValuePtr evalFn(const ValueVector& nodes, EnvironmentPtr env);
-	ValuePtr evalMacroExpand(const ValueVector& nodes, EnvironmentPtr env);
 	ValuePtr evalQuasiQuoteExpand(const ValueVector& nodes);
 	ValuePtr evalQuote(const ValueVector& nodes);
 	ValuePtr evalTry(const ValueVector& nodes, EnvironmentPtr env);
@@ -45,6 +41,7 @@ private:
 	void evalDo(const ValueVector& nodes, EnvironmentPtr env);
 	void evalIf(const ValueVector& nodes, EnvironmentPtr env);
 	void evalLet(const ValueVector& nodes, EnvironmentPtr env);
+	void evalMacroExpand1(const ValueVector& nodes, EnvironmentPtr env);
 	void evalQuasiQuote(const ValueVector& nodes, EnvironmentPtr env);
 	void evalWhile(const ValueVector& nodes, EnvironmentPtr env);