Enhance core string types with built-in manipulation methods by integrating common string operations, previously in extensions, as methods on the StringValue class.

common/BUILD

@@ -628,10 +628,12 @@ cc_library(
         ":native_type",
         ":optional_ref",
         ":type",
+        ":typeinfo",
         ":unknown",
         ":value_kind",
         "//base:attributes",
         "//common/internal:byte_string",
+        "//common/internal:reference_count",
         "//eval/internal:cel_value_equal",
         "//eval/public:cel_value",
         "//eval/public:message_wrapper",
@@ -656,6 +658,7 @@ cc_library(
         "//internal:utf8",
         "//internal:well_known_types",
         "//runtime:runtime_options",
+        "//runtime/internal:errors",
         "@com_google_absl//absl/base",
         "@com_google_absl//absl/base:core_headers",
         "@com_google_absl//absl/base:no_destructor",

common/value.h

@@ -39,6 +39,7 @@
 #include "common/native_type.h"
 #include "common/optional_ref.h"
 #include "common/type.h"
+#include "common/typeinfo.h"
 #include "common/value_kind.h"
 #include "common/values/bool_value.h"  // IWYU pragma: export
 #include "common/values/bytes_value.h"  // IWYU pragma: export
@@ -2537,6 +2538,75 @@ ErrorValueAssign::operator()(absl::Status status) const {
   return common_internal::ImplicitlyConvertibleStatus();
 }
 
+inline absl::StatusOr<Value> StringValue::Join(
+    const ListValue& list,
+    const google::protobuf::DescriptorPool* absl_nonnull descriptor_pool,
+    google::protobuf::MessageFactory* absl_nonnull message_factory,
+    google::protobuf::Arena* absl_nonnull arena) const {
+  ABSL_DCHECK(descriptor_pool != nullptr);
+  ABSL_DCHECK(message_factory != nullptr);
+  ABSL_DCHECK(arena != nullptr);
+
+  Value result;
+  CEL_RETURN_IF_ERROR(
+      Join(list, descriptor_pool, message_factory, arena, &result));
+  return result;
+}
+
+inline absl::StatusOr<Value> StringValue::Split(
+    const StringValue& delimiter, int64_t limit,
+    google::protobuf::Arena* absl_nonnull arena) const {
+  ABSL_DCHECK(arena != nullptr);
+
+  Value result;
+  CEL_RETURN_IF_ERROR(Split(delimiter, limit, arena, &result));
+  return result;
+}
+
+inline absl::Status StringValue::Split(const StringValue& delimiter,
+                                       google::protobuf::Arena* absl_nonnull arena,
+                                       Value* absl_nonnull result) const {
+  ABSL_DCHECK(arena != nullptr);
+  ABSL_DCHECK(result != nullptr);
+
+  return Split(delimiter, /*limit=*/-1, arena, result);
+}
+
+inline absl::StatusOr<Value> StringValue::Split(
+    const StringValue& delimiter, google::protobuf::Arena* absl_nonnull arena) const {
+  ABSL_DCHECK(arena != nullptr);
+
+  return Split(delimiter, /*limit=*/-1, arena);
+}
+
+inline absl::StatusOr<Value> StringValue::Replace(
+    const StringValue& needle, const StringValue& replacement, int64_t limit,
+    google::protobuf::Arena* absl_nonnull arena) const {
+  ABSL_DCHECK(arena != nullptr);
+
+  Value result;
+  CEL_RETURN_IF_ERROR(Replace(needle, replacement, limit, arena, &result));
+  return result;
+}
+
+inline absl::Status StringValue::Replace(const StringValue& needle,
+                                         const StringValue& replacement,
+                                         google::protobuf::Arena* absl_nonnull arena,
+                                         Value* absl_nonnull result) const {
+  ABSL_DCHECK(arena != nullptr);
+  ABSL_DCHECK(result != nullptr);
+
+  return Replace(needle, replacement, /*limit=*/-1, arena, result);
+}
+
+inline absl::StatusOr<Value> StringValue::Replace(
+    const StringValue& needle, const StringValue& replacement,
+    google::protobuf::Arena* absl_nonnull arena) const {
+  ABSL_DCHECK(arena != nullptr);
+
+  return Replace(needle, replacement, /*limit=*/-1, arena);
+}
+
 namespace common_internal {
 
 template <typename Base>