Enable integer serialization.

nth/io/serialize/BUILD

@@ -12,6 +12,19 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "round_trip",
+    testonly = True,
+    hdrs = ["round_trip.h"],
+    deps = [
+        "//nth/io/serialize",
+        "//nth/io/serialize:deserialize",
+        "//nth/io/writer:string",
+        "//nth/io/reader:string",
+        "//nth/test",
+    ],
+)
+
 cc_test(
     name = "round_trip_test",
     srcs = ["round_trip_test.cc"],

nth/io/serialize/round_trip.h

@@ -0,0 +1,34 @@
+#ifndef NTH_IO_SERIALIZE_ROUND_TRIP_H
+#define NTH_IO_SERIALIZE_ROUND_TRIP_H
+
+#include <concepts>
+#include <string>
+
+#include "nth/io/reader/string.h"
+#include "nth/io/serialize/deserialize.h"
+#include "nth/io/serialize/serialize.h"
+#include "nth/io/writer/string.h"
+#include "nth/test/test.h"
+
+NTH_TEST("nth/io/serialize/round-trip",
+         std::equality_comparable auto const &original) {
+  std::decay_t<decltype(original)> object;
+
+  {
+    std::string content;
+
+    {
+      nth::io::string_writer s(content);
+      NTH_ASSERT(nth::io::serialize(s, original));
+    }
+
+    {
+      nth::io::string_reader d(content);
+      NTH_ASSERT(nth::io::deserialize(d, object));
+    }
+  }
+
+  NTH_EXPECT(original == object);
+}
+
+#endif  // NTH_IO_SERIALIZE_ROUND_TRIP_H

nth/numeric/BUILD

@@ -4,7 +4,11 @@ cc_library(
     name = "integer",
     hdrs = ["integer.h"],
     srcs = ["integer.cc"],
-    deps = ["//nth/debug"],
+    deps = [
+        "//nth/debug",
+        "//nth/io/serialize",
+        "//nth/io/serialize:deserialize",
+    ],
 )
 
 cc_library(
@@ -22,6 +26,7 @@ cc_test(
     deps = [
       ":integer",
       ":test_traits",
+      "//nth/io/serialize:round_trip",
       "//nth/test:main",
     ],
 )

nth/numeric/integer.h

@@ -9,6 +9,8 @@
 #include <string_view>
 
 #include "nth/debug/debug.h"
+#include "nth/io/serialize/deserialize.h"
+#include "nth/io/serialize/serialize.h"
 #include "nth/meta/concepts.h"
 
 namespace nth {
@@ -124,6 +126,44 @@ struct integer {
                                  n.words().size());
   }
 
+  friend bool NthSerialize(auto &s, integer const &n) {
+    if (not nth::io::serialize_fixed(s, static_cast<bool>(n.sign_)) or
+        not nth::io::serialize_integer(s, n.size_)) {
+      return false;
+    }
+    for (uintptr_t w : n.words()) {
+      if (not nth::io::serialize_fixed(s, w)) { return false; }
+    }
+    return true;
+  }
+
+  friend bool NthDeserialize(auto &d, integer &n) {
+    bool sig;
+    uintptr_t size;
+    if (not nth::io::deserialize_fixed(d, sig) or
+        not nth::io::deserialize_integer(d, size)) {
+      return false;
+    }
+    n.sign_ = sig;
+    n.size_ = size;
+    switch (size) {
+      case 0:return true;
+      case 1: return nth::io::deserialize_fixed(d, n.data_[0]);
+      case 2:
+        return nth::io::deserialize_fixed(d, n.data_[0]) and
+               nth::io::deserialize_fixed(d, n.data_[1]);
+      default: {
+        uintptr_t *ptr = new uintptr_t[size];
+        n.data_[0]       = reinterpret_cast<uintptr_t>(ptr);
+        n.data_[1]       = size;
+        for (size_t i = 0; i < size; ++i) {
+          if (not nth::io::deserialize_fixed(d, *ptr++)) { return false; }
+        }
+        return true;
+      } break;
+    }
+  }
+
  private:
   void ResizeTo(uint64_t n);
 

nth/numeric/integer_test.cc

@@ -1,5 +1,6 @@
 #include "nth/numeric/integer.h"
 
+#include "nth/io/serialize/round_trip.h"
 #include "nth/numeric/test_traits.h"
 #include "nth/strings/format/universal.h"
 #include "nth/test/test.h"
@@ -454,5 +455,9 @@ NTH_TEST("integer/addition/different-signs") {
              -1);
 }
 
+NTH_INVOKE_TEST("nth/io/serialize/round-trip") {
+  for (auto const &v : SampleValues()) { co_yield v; }
+}
+
 }  // namespace
 }  // namespace nth