From 1e76d4599a13b7003a8857728805b3de495f6897 Mon Sep 17 00:00:00 2001
From: Riyyi <riyyi3@gmail.com>
Date: Tue, 28 Mar 2023 22:51:28 +0200
Subject: [PATCH] Meta+Env: Fix count on nil value

---
 CMakeLists.txt    |  4 ++++
 src/functions.cpp | 22 +++++++++++++---------
 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5a6fd20..cf5cc68 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -95,3 +95,7 @@ add_dependencies(test2 ${PROJECT})
 add_custom_target(test3
     COMMAND env STEP=step_env MAL_IMPL=js ../vendor/mal/runtest.py --deferrable --optional ../vendor/mal/tests/step3_env.mal -- ./${PROJECT})
 add_dependencies(test3 ${PROJECT})
+
+add_custom_target(test4
+    COMMAND env STEP=step_env MAL_IMPL=js ../vendor/mal/runtest.py --deferrable --optional ../vendor/mal/tests/step4_if_fn_do.mal -- ./${PROJECT})
+add_dependencies(test4 ${PROJECT})
diff --git a/src/functions.cpp b/src/functions.cpp
index c7c97ab..ec8fb55 100644
--- a/src/functions.cpp
+++ b/src/functions.cpp
@@ -233,20 +233,24 @@ void GlobalEnvironment::isEmpty()
 void GlobalEnvironment::count()
 {
 	auto count = [this](std::list<ASTNodePtr> nodes) -> ASTNodePtr {
-		if (nodes.size() > 1) {
+		if (nodes.size() != 1) {
 			Error::the().addError(format("wrong number of arguments: {}, {}", m_current_key, nodes.size() - 1));
 			return nullptr;
 		}
 
 		size_t result = 0;
-
-		for (auto node : nodes) {
-			if (!is<List>(node.get())) {
-				Error::the().addError(format("wrong argument type: list, '{}'", node));
-				return nullptr;
-			}
-
-			result = std::static_pointer_cast<List>(node)->size();
+		if (is<Value>(nodes.front().get()) && std::static_pointer_cast<Value>(nodes.front())->state() == Value::Nil) {
+			// result = 0
+		}
+		else if (!is<List>(nodes.front().get())) {
+			result = std::static_pointer_cast<List>(nodes.front())->size();
+		}
+		else if (!is<Vector>(nodes.front().get())) {
+			result = std::static_pointer_cast<Vector>(nodes.front())->size();
+		}
+		else {
+			Error::the().addError(format("wrong argument type: list, '{}'", nodes));
+			return nullptr;
 		}
 
 		// FIXME: Add numeric_limits check for implicit cast: size_t > int64_t