diff --git a/src/functions.cpp b/src/functions.cpp
index 73ba45f..aa92cc2 100644
--- a/src/functions.cpp
+++ b/src/functions.cpp
@@ -7,6 +7,7 @@
 #include <memory> // std::static_pointer_cast
 #include <string>
 
+#include "ruc/file.h"
 #include "ruc/format/format.h"
 
 #include "ast.h"
@@ -371,6 +372,58 @@ ADD_FUNCTION(
 		return makePtr<Value>((result) ? Value::True : Value::False);
 	});
 
+ADD_FUNCTION(
+	"read-string",
+	{
+		if (nodes.size() != 1) {
+			Error::the().add(format("wrong number of arguments: read-string, {}", nodes.size()));
+			return nullptr;
+		}
+
+		if (!is<String>(nodes.front().get())) {
+			Error::the().add(format("wrong argument type: string, '{}'", nodes.front()));
+			return nullptr;
+		}
+
+		std::string input = std::static_pointer_cast<String>(nodes.front())->data();
+
+		return read(input);
+	});
+
+ADD_FUNCTION(
+	"slurp",
+	{
+		if (nodes.size() != 1) {
+			Error::the().add(format("wrong number of arguments: slurp, {}", nodes.size()));
+			return nullptr;
+		}
+
+		if (!is<String>(nodes.front().get())) {
+			Error::the().add(format("wrong argument type: string, '{}'", nodes.front()));
+			return nullptr;
+		}
+
+		std::string path = std::static_pointer_cast<String>(nodes.front())->data();
+
+		auto file = ruc::File(path);
+
+		return makePtr<String>(file.data());
+	});
+
+
+ADD_FUNCTION(
+	"eval",
+	{
+		if (nodes.size() != 1) {
+			Error::the().add(format("wrong number of arguments: eval, {}", nodes.size()));
+			return nullptr;
+		}
+
+		return eval(nodes.front(), nullptr);
+	});
+
+// -----------------------------------------
+
 void installFunctions(EnvironmentPtr env)
 {
 	for (const auto& [name, lambda] : s_functions) {
diff --git a/src/step6_file.cpp b/src/step6_file.cpp
index 08d80db..b60ff02 100644
--- a/src/step6_file.cpp
+++ b/src/step6_file.cpp
@@ -53,6 +53,10 @@ auto read(std::string_view input) -> ASTNodePtr
 
 auto eval(ASTNodePtr ast, EnvironmentPtr env) -> ASTNodePtr
 {
+	if (env == nullptr) {
+		env = s_outer_env;
+	}
+
 	Eval eval(ast, env);
 	eval.eval();
 
@@ -76,6 +80,8 @@ static auto rep(std::string_view input, EnvironmentPtr env) -> std::string
 
 static std::string_view lambdaTable[] = {
 	"(def! not (fn* (cond) (if cond false true)))",
+	"(def! load-file (fn* (filename) \
+	    (eval (read-string (str \"(do \" (slurp filename) \"\nnil)\")))))",
 };
 
 static auto installLambdas(EnvironmentPtr env) -> void