From 12d6b8ec885a82405f37302342e22bc04d08021d Mon Sep 17 00:00:00 2001
From: Riyyi <riyyi3@gmail.com>
Date: Mon, 1 May 2023 10:24:38 +0200
Subject: [PATCH] Everywhere: Change macro into a separate type

---
 src/ast.cpp               | 17 +++++++++++------
 src/ast.h                 | 23 +++++++++++++++++++----
 src/eval-special-form.cpp |  2 +-
 src/eval.cpp              |  3 +--
 src/functions.cpp         | 16 ++++------------
 src/printer.cpp           |  7 +++++--
 6 files changed, 41 insertions(+), 27 deletions(-)

diff --git a/src/ast.cpp b/src/ast.cpp
index a26b4d9..1fc165e 100644
--- a/src/ast.cpp
+++ b/src/ast.cpp
@@ -260,11 +260,10 @@ Lambda::Lambda(const std::vector<std::string>& bindings, ValuePtr body, Environm
 {
 }
 
-Lambda::Lambda(std::shared_ptr<Lambda> that, bool is_macro)
-	: m_bindings(that->m_bindings)
-	, m_body(that->m_body)
-	, m_env(that->m_env)
-	, m_is_macro(is_macro)
+Lambda::Lambda(const Lambda& that)
+	: m_bindings(that.m_bindings)
+	, m_body(that.m_body)
+	, m_env(that.m_env)
 {
 }
 
@@ -273,7 +272,13 @@ Lambda::Lambda(const Lambda& that, ValuePtr meta)
 	, m_bindings(that.m_bindings)
 	, m_body(that.m_body)
 	, m_env(that.m_env)
-	, m_is_macro(that.m_is_macro)
+{
+}
+
+// -----------------------------------------
+
+Macro::Macro(const Lambda& that)
+	: Lambda(that)
 {
 }
 
diff --git a/src/ast.h b/src/ast.h
index f064c3f..cbbfbf0 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -58,6 +58,7 @@ public:
 	virtual bool isCallable() const { return false; }
 	virtual bool isFunction() const { return false; }
 	virtual bool isLambda() const { return false; }
+	virtual bool isMacro() const { return false; }
 	virtual bool isAtom() const { return false; }
 
 protected:
@@ -343,17 +344,16 @@ private:
 
 // -----------------------------------------
 
-class Lambda final : public Callable {
+class Lambda : public Callable {
 public:
 	Lambda(const std::vector<std::string>& bindings, ValuePtr body, EnvironmentPtr env);
-	Lambda(std::shared_ptr<Lambda> that, bool is_macro);
+	Lambda(const Lambda& that);
 	Lambda(const Lambda& that, ValuePtr meta);
 	virtual ~Lambda() = default;
 
 	const std::vector<std::string>& bindings() const { return m_bindings; }
 	ValuePtr body() const { return m_body; }
 	EnvironmentPtr env() const { return m_env; }
-	bool isMacro() const { return m_is_macro; }
 
 	WITH_META(Lambda);
 
@@ -363,7 +363,19 @@ private:
 	const std::vector<std::string> m_bindings;
 	const ValuePtr m_body;
 	const EnvironmentPtr m_env;
-	const bool m_is_macro { false };
+};
+
+// -----------------------------------------
+
+class Macro final : public Lambda {
+public:
+	Macro(const Lambda& that);
+
+	WITH_NO_META();
+
+private:
+	virtual bool isLambda() const override { return false; }
+	virtual bool isMacro() const override { return true; }
 };
 
 // -----------------------------------------
@@ -424,6 +436,9 @@ inline bool Value::fastIs<Function>() const { return isFunction(); }
 template<>
 inline bool Value::fastIs<Lambda>() const { return isLambda(); }
 
+template<>
+inline bool Value::fastIs<Macro>() const { return isMacro(); }
+
 template<>
 inline bool Value::fastIs<Atom>() const { return isAtom(); }
 // clang-format on
diff --git a/src/eval-special-form.cpp b/src/eval-special-form.cpp
index 0c8bb1f..7b51c77 100644
--- a/src/eval-special-form.cpp
+++ b/src/eval-special-form.cpp
@@ -63,7 +63,7 @@ ValuePtr Eval::evalDefMacro(const std::list<ValuePtr>& nodes, EnvironmentPtr env
 	}
 
 	// Modify existing environment
-	return env->set(symbol->symbol(), makePtr<Lambda>(lambda, true));
+	return env->set(symbol->symbol(), makePtr<Macro>(*lambda));
 }
 
 // (fn* (x) x)
diff --git a/src/eval.cpp b/src/eval.cpp
index 2c717f0..20aeffe 100644
--- a/src/eval.cpp
+++ b/src/eval.cpp
@@ -210,9 +210,8 @@ bool Eval::isMacroCall(ValuePtr ast, EnvironmentPtr env)
 
 	auto symbol = dynamic_cast<Symbol*>(front)->symbol();
 	auto value = env->get(symbol).get();
-	auto lambda = dynamic_cast<Lambda*>(value);
 
-	if (lambda == nullptr || !lambda->isMacro()) {
+	if (!is<Macro>(value)) {
 		return false;
 	}
 
diff --git a/src/functions.cpp b/src/functions.cpp
index b342bba..972e408 100644
--- a/src/functions.cpp
+++ b/src/functions.cpp
@@ -638,12 +638,9 @@ ADD_FUNCTION(
 				result = false;
 				break;
 			}
-			if (is<Lambda>(node.get())) {
-				auto lambda = std::static_pointer_cast<Lambda>(node);
-				if (lambda->isMacro()) {
-					result = false;
-					break;
-				}
+			if (is<Macro>(node.get())) {
+				result = false;
+				break;
 			}
 		}
 
@@ -660,12 +657,7 @@ ADD_FUNCTION(
 		}
 
 		for (auto node : nodes) {
-			if (!is<Lambda>(node.get())) {
-				result = false;
-				break;
-			}
-			auto lambda = std::static_pointer_cast<Lambda>(node);
-			if (!lambda->isMacro()) {
+			if (!is<Macro>(node.get())) {
 				result = false;
 				break;
 			}
diff --git a/src/printer.cpp b/src/printer.cpp
index 8ca2cf5..1eecf9f 100644
--- a/src/printer.cpp
+++ b/src/printer.cpp
@@ -139,8 +139,11 @@ void Printer::printImpl(ValuePtr node, bool print_readably)
 	}
 	else if (is<Lambda>(node_raw_ptr)) {
 		printSpacing();
-		auto lambda = std::static_pointer_cast<Lambda>(node);
-		m_print += format("#<user-{}>({:p})", (lambda->isMacro()) ? "macro" : "function", node_raw_ptr);
+		m_print += format("#<user-function>({:p})", node_raw_ptr);
+	}
+	else if (is<Macro>(node_raw_ptr)) {
+		printSpacing();
+		m_print += format("#<user-macro>({:p})", node_raw_ptr);
 	}
 	else if (is<Atom>(node_raw_ptr)) {
 		printSpacing();