diff --git a/bin/pre.slime b/bin/pre.slime
index 46a06b9..f838b97 100644
--- a/bin/pre.slime
+++ b/bin/pre.slime
@@ -1,5 +1,5 @@
 (define-syntax when (condition :rest body)
-  "alsdkjalsk djalksdj alksjd lakjd"
+  "Doc String for 'when'"
   `(if ,condition ,(pair prog body) nil))
 
 (define-syntax unless (condition :rest body)
@@ -238,4 +238,4 @@ las argument."
   (eval (pair printf-quoted (extend (list :@sep (eval sep) :@end (eval end)) args))))
 
 (define-syntax pe (expr)
-  `(printf ,expr "evaluates to" (eval ,expr)))
+  `(printf ',expr "evaluates to" ,(eval expr)))
diff --git a/src/built_ins.cpp b/src/built_ins.cpp
index 6c93310..2b695e1 100644
--- a/src/built_ins.cpp
+++ b/src/built_ins.cpp
@@ -34,17 +34,14 @@ proc built_in_load(String* file_name, Environment* env) -> Lisp_Object* {
     if (file_content) {
         Lisp_Object* result = Memory::nil;
         Lisp_Object_Array_List* program;
-        try {
-            program = Parser::parse_program(file_name, file_content);
-        }
+        try program = Parser::parse_program(file_name, file_content);
+
         for (int i = 0; i < program->next_index; ++i) {
-            try {
-                result = eval_expr(program->data[i], env);
-            }
+            try result = eval_expr(program->data[i], env);            
         }
         return result;
     } else {
-        create_generic_error("The file '%s' was not found", file_name);
+        create_generic_error("The file '%s' was not found", Memory::get_c_str(file_name));
         return nullptr;
     }
 }
diff --git a/src/eval.cpp b/src/eval.cpp
index e7c1066..a5f1f38 100644
--- a/src/eval.cpp
+++ b/src/eval.cpp
@@ -19,7 +19,7 @@ proc apply_arguments_to_function(Lisp_Object* arguments, Function* function) ->
 
     String_Array_List* read_in_keywords = create_String_array_list();
 
-    if (Memory::get_type(arguments) == Lisp_Object_Type::Nil)
+    if (arguments == Memory::nil)
         goto checks;
     // keyword arguments: use all given ones and keep track of the
     // added ones (array list), if end of parameters in encountered or
diff --git a/src/testing.cpp b/src/testing.cpp
index e3a05af..aaf7884 100644
--- a/src/testing.cpp
+++ b/src/testing.cpp
@@ -480,14 +480,20 @@ proc test_singular_t_and_nil() -> testresult {
 
 proc test_file(const char* file) -> testresult {
     Memory::reset();
+    assert_no_error();
+
     Environment* env = Memory::create_built_ins_environment();
+    assert_no_error();
 
     Parser::init(env);
+    assert_no_error();
 
     built_in_load(Memory::create_string("pre.slime"), env);
-    Lisp_Object* result = built_in_load(Memory::create_string(file), env);
+    assert_no_error();
 
+    Lisp_Object* result = built_in_load(Memory::create_string(file), env);
     assert_no_error();
+
     return pass;
 }