Eval: Add and/or special forms

src/eval-special-form.cpp

@@ -171,6 +171,30 @@ ValuePtr Eval::evalTry(const ValueVector& nodes, EnvironmentPtr env)
 
 // -----------------------------------------
 
+// (and 1 2 3)
+void Eval::evalAnd(const ValueVector& nodes, EnvironmentPtr env)
+{
+	ValuePtr result;
+	for (auto node : nodes) {
+		m_ast = node;
+		m_env = env;
+		result = evalImpl();
+
+		if (is<Constant>(result.get())) {
+			VALUE_CAST(constant, Constant, result, void());
+			if (constant->state() == Constant::Nil || constant->state() == Constant::False) {
+				m_ast = makePtr<Constant>(Constant::Nil);
+				m_env = env;
+				return; // TCO
+			}
+		}
+	}
+
+	m_ast = result;
+	m_env = env;
+	return; // TCO
+}
+
 // (do 1 2 3)
 void Eval::evalDo(const ValueVector& nodes, EnvironmentPtr env)
 {
@@ -295,6 +319,36 @@ void Eval::evalMacroExpand1(const ValueVector& nodes, EnvironmentPtr env)
 
 // -----------------------------------------
 
+// (or 1 2 3)
+void Eval::evalOr(const ValueVector& nodes, EnvironmentPtr env)
+{
+	ValuePtr result;
+	for (auto node : nodes) {
+		m_ast = node;
+		m_env = env;
+		result = evalImpl();
+
+		if (!is<Constant>(result.get())) {
+			m_ast = result;
+			m_env = env;
+			return; // TCO
+		}
+
+		VALUE_CAST(constant, Constant, result, void());
+		if (constant->state() == Constant::True) {
+			m_ast = result;
+			m_env = env;
+			return; // TCO
+		}
+	}
+
+	m_ast = makePtr<Constant>(Constant::Nil);
+	m_env = env;
+	return; // TCO
+}
+
+// -----------------------------------------
+
 static bool isSymbol(ValuePtr value, const std::string& symbol)
 {
 	if (!is<Symbol>(value.get())) {

src/eval.cpp

@@ -93,6 +93,10 @@ ValuePtr Eval::evalImpl()
 				return evalTry(nodes, env);
 			}
 			// Tail call optimized functions
+			if (symbol == "and") {
+				evalAnd(nodes, env);
+				continue; // TCO
+			}
 			if (symbol == "do") {
 				evalDo(nodes, env);
 				continue; // TCO
@@ -109,6 +113,10 @@ ValuePtr Eval::evalImpl()
 				evalMacroExpand1(nodes, env);
 				continue; // TCO
 			}
+			if (symbol == "or") {
+				evalOr(nodes, env);
+				continue; // TCO
+			}
 			if (symbol == "quasiquote") {
 				evalQuasiQuote(nodes, env);
 				continue; // TCO

src/eval.h

@@ -38,10 +38,12 @@ private:
 	ValuePtr evalQuote(const ValueVector& nodes);
 	ValuePtr evalTry(const ValueVector& nodes, EnvironmentPtr env);
 
+	void evalAnd(const ValueVector& nodes, EnvironmentPtr env);
 	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 evalOr(const ValueVector& nodes, EnvironmentPtr env);
 	void evalQuasiQuote(const ValueVector& nodes, EnvironmentPtr env);
 	void evalWhile(const ValueVector& nodes, EnvironmentPtr env);