diff --git a/src/common.cpp b/src/common.cpp
index 8b8f52e..287cc90 100644
--- a/src/common.cpp
+++ b/src/common.cpp
@@ -4,6 +4,7 @@
 #include "error.hpp"
 #include "pod.hpp"
 #include "utf8.hpp"
+#include "writer.hpp"
 
 Syntax::Syntax(String filename, String modulename, Value expression) {}
 
@@ -163,6 +164,12 @@ Result<void> debug_print(Arena& arena, String& val) {
   return Result<void>();
 }
 
+Result<void> debug_print(Arena& arena, Value& val) {
+  auto w = Writer(arena);
+  auto s = TRY(w.write_one(val));
+  return debug_print(arena, s);
+}
+
 Result<Value> Array::get(Arena& arena, uint64_t idx) {
   if (idx >= _value->size) return ErrorCode::IndexOutOfRange;
   auto val = _value->data[idx].get(pod());
diff --git a/src/common.hpp b/src/common.hpp
index 4b49e99..d5d0b99 100644
--- a/src/common.hpp
+++ b/src/common.hpp
@@ -330,7 +330,26 @@ class String : public Object {
   virtual Tag tag() final { return Tag::String; }
   virtual PodObject* pod() final { return _value.get(); }
   virtual Result<short> cmp(Object& rhs) final { return -TRY(rhs.cmp(*this)); }
-  virtual Result<short> cmp(String& rhs) final { return 0; }
+  virtual Result<short> cmp(String& rhs) final {
+    auto lsize = size();
+    auto rsize = rhs.size();
+    uint64_t i = 0;
+    uint64_t j = 0;
+    while (1) {
+      if (i == lsize && j == lsize) return 0;
+
+      short cmp = short(i == lsize) - short(j == rsize);
+      if (cmp != 0) return cmp;
+
+      char32_t lc = _value->data[i];
+      char32_t rc = rhs._value->data[j];
+      cmp = (lc > rc) - (lc < rc);
+      if (cmp != 0) return cmp;
+      i++;
+      j++;
+    }
+    return 0;
+  }
 
   virtual void move(Object* obj) final { new (obj) String(std::move(_value)); }
 
@@ -654,6 +673,10 @@ class Value {
     return Value(TRY(Int64::create(arena, value)));
   }
 
+  static Result<Value> create(Arena& arena, const char* value) {
+    return Value(TRY(String::create(arena, value)));
+  }
+
   template <class T>
   bool is() {
     return dynamic_cast<T*>((Object*)buf) != nullptr;
@@ -688,6 +711,7 @@ Result<Value> syntax_unwrap(Value& val);
 Result<Value> reverse(Arena& arena, Value& val);
 
 Result<void> debug_print(Arena& arena, String& val);
+Result<void> debug_print(Arena& arena, Value& val);
 
 template <class K, class V>
 Result<Dict> Dict::insert(Arena& arena, const K& key, const V& value) {
diff --git a/src/writer.cpp b/src/writer.cpp
index 35026c8..6ab1182 100644
--- a/src/writer.cpp
+++ b/src/writer.cpp
@@ -216,3 +216,8 @@ Result<String> Writer::write_dict(Dict& val) {
   res = TRY(res.concat(_arena, "}"));
   return res;
 }
+
+Result<String> write_one(Arena& arena, Value& value) {
+  auto w = Writer(arena);
+  return w.write_one(value);
+}
diff --git a/src/writer.hpp b/src/writer.hpp
index 8384e1d..c2a49be 100644
--- a/src/writer.hpp
+++ b/src/writer.hpp
@@ -25,3 +25,14 @@ class Writer {
 
   Arena& _arena;
 };
+
+Result<String> write_one(Arena& arena, Value& value);
+
+template <class T>
+Result<String> write_one(Arena& arena, T& value)
+  requires std::derived_from<T, Object>
+{
+  auto w = Writer(arena);
+  auto v = DIEX(value.copy(arena));
+  return w.write_one(v);
+}
diff --git a/test/dict.cpp b/test/dict.cpp
index 38a410f..0ed6494 100644
--- a/test/dict.cpp
+++ b/test/dict.cpp
@@ -15,10 +15,7 @@ TEST_CASE(dict_insert) {
   d = DIEX(d.insert(arena, 0, 5));
   d = DIEX(d.insert(arena, 2, 6));
 
-  auto w = Writer(arena);
+  auto s = DIEX(write_one(arena, d));
 
-  auto dd = DIEX(d.copy(arena));
-  auto s = DIEX(w.write_one(dd));
-
-  DIEX(debug_print(arena, s));
+  ASSERT_EQUALS(s, "{0 5 1 3 2 6 3 3}");
 }
diff --git a/test/test.hpp b/test/test.hpp
index 120669f..0d889bf 100644
--- a/test/test.hpp
+++ b/test/test.hpp
@@ -1,6 +1,11 @@
 #pragma once
 
+#include <algorithm>
 #include <cstdint>
+#include <cstdio>
+
+#include "common.hpp"
+#include "result.hpp"
 
 const uint64_t MAX_TESTS = 1024 * 1024;
 static void (*tests[MAX_TESTS])() = {0};
@@ -37,4 +42,51 @@ bool run_tests() {
 
 #define TEST_CASE(fun_) TEST_CASE_IMPL(MACRO_CONCAT(fun_, _COUNTER_))
 
+template <class T>
+struct Capture {
+  Capture(T& value) : value(value) {}
+  T& value;
+};
+
+template <class T>
+struct Capture<T&> {
+  Capture(T& value) : value(value) {}
+  T& value;
+};
+
+template <class T>
+struct Capture<T&&> {
+  Capture(T&& value) : value(value) {}
+  T value;
+};
+
+Value& to_value(Arena& arena, Value& val) { return val; }
+
+template <class T>
+  requires std::derived_from<T, Object>
+Value to_value(Arena& arena, T& val) {
+  return DIEX(val.copy(arena));
+}
+
+template <class T>
+  requires(!std::derived_from<T, Object>)
+Value to_value(Arena& arena, T& val) {
+  return DIEX(Value::create(arena, val));
+}
+
+#define ASSERT_EQUALS(lhs, rhs)                                           \
+  do {                                                                    \
+    auto l = Capture(lhs);                                                \
+    auto r = Capture(rhs);                                                \
+    auto lv = to_value(arena, l.value);                                   \
+    auto rv = to_value(arena, r.value);                                   \
+    short c = DIEX(lv.cmp(rv));                                           \
+    if (c != 0) {                                                         \
+      fprintf(stderr, "Values not equal at %s:%d\n", __FILE__, __LINE__); \
+      debug_print(arena, lv);                                             \
+      debug_print(arena, rv);                                             \
+      exit(EXIT_FAILURE);                                                 \
+    }                                                                     \
+  } while (0)
+
 int main() { return run_tests() ? 0 : 1; }