Everywhere: Initial implementation of step3

src/environment.h

@@ -6,146 +6,43 @@
 
 #pragma once
 
-#include <cstdint> // int64_t
-#include <iostream>
-#include <memory>
-#include <span>
-#include <string_view>
+#include <string>
 #include <unordered_map>
-#include <vector>
-
-#include "error.h"
-#include "ruc/format/color.h"
-#include "ruc/singleton.h"
 
 #include "ast.h"
-#include "types.h"
 
 namespace blaze {
 
+class Environment;
+typedef std::shared_ptr<Environment> EnvironmentPtr;
+
 class Environment {
 public:
 	Environment() = default;
+	Environment(EnvironmentPtr outer);
 	virtual ~Environment() = default;
 
-	ASTNodePtr lookup(const std::string& symbol)
-	{
-		m_current_key = symbol;
-		return m_values.find(symbol) != m_values.end() ? m_values[symbol] : nullptr;
-	}
+	bool exists(const std::string& symbol);
+	ASTNodePtr set(const std::string& symbol, ASTNodePtr value);
+	ASTNodePtr get(const std::string& symbol);
 
 protected:
 	std::string m_current_key;
 	std::unordered_map<std::string, ASTNodePtr> m_values;
+	EnvironmentPtr m_outer { nullptr };
 };
 
 class GlobalEnvironment final : public Environment {
 public:
-	GlobalEnvironment()
-	{
-		// TODO: Add more native functions
-		// TODO: Move the functions to their own file
-		auto add = [](std::span<ASTNodePtr> nodes) -> ASTNodePtr {
-			int64_t result = 0;
-
-			for (auto node : nodes) {
-				if (!is<Number>(node.get())) {
-					Error::the().addError(format("wrong type argument: number-or-marker-p, '{}'", node));
-					return nullptr;
-				}
-
-				result += static_pointer_cast<Number>(node)->number();
-			}
-
-			return makePtr<Number>(result);
-		};
-
-		auto sub = [](std::span<ASTNodePtr> nodes) -> ASTNodePtr {
-			int64_t result = 0;
-
-			if (nodes.size() == 0) {
-				return makePtr<Number>(0);
-			}
-
-			for (auto node : nodes) {
-				if (!is<Number>(node.get())) {
-					Error::the().addError(format("wrong type argument: number-or-marker-p, '{}'", node));
-					return nullptr;
-				}
-			}
-
-			// Start with the first number
-			result += static_pointer_cast<Number>(nodes[0])->number();
-
-			// Skip the first node
-			for (auto it = std::next(nodes.begin()); it != nodes.end(); ++it) {
-				result -= static_pointer_cast<Number>(*it)->number();
-			}
-
-			return makePtr<Number>(result);
-		};
-
-		auto mul = [](std::span<ASTNodePtr> nodes) -> ASTNodePtr {
-			int64_t result = 1;
-
-			for (auto node : nodes) {
-				if (!is<Number>(node.get())) {
-					Error::the().addError(format("wrong type argument: number-or-marker-p, '{}'", node));
-					return nullptr;
-				}
-
-				result *= static_pointer_cast<Number>(node)->number();
-			}
-
-			return makePtr<Number>(result);
-		};
-
-		auto div = [this](std::span<ASTNodePtr> nodes) -> ASTNodePtr {
-			double result = 0;
-
-			if (nodes.size() == 0) {
-				Error::the().addError(format("wrong number of arguments: {}, 0", m_current_key));
-				return nullptr;
-			}
-
-			for (auto node : nodes) {
-				if (!is<Number>(node.get())) {
-					Error::the().addError(format("wrong type argument: number-or-marker-p, '{}'", node));
-					return nullptr;
-				}
-			}
-
-			// Start with the first number
-			result += static_pointer_cast<Number>(nodes[0])->number();
-
-			// Skip the first node
-			for (auto it = std::next(nodes.begin()); it != nodes.end(); ++it) {
-				result /= static_pointer_cast<Number>(*it)->number();
-			}
-
-			return makePtr<Number>((int64_t)result);
-		};
-
-		m_values.emplace("+", makePtr<Function>(add));
-		m_values.emplace("-", makePtr<Function>(sub));
-		m_values.emplace("*", makePtr<Function>(mul));
-		m_values.emplace("/", makePtr<Function>(div));
-	}
+	GlobalEnvironment();
 	virtual ~GlobalEnvironment() = default;
+
+private:
+	// TODO: Add more native functions
+	void add();
+	void sub();
+	void mul();
+	void div();
 };
 
 } // namespace blaze
-
-// associative data structure that maps symbols (the keys) to values
-
-// values = anything, including other symbols.
-// an environment is like a hash table
-
-// value can map to:
-// list
-// vector
-// hash-map
-// symbol
-// number
-// string
-// function