Add strings.format CEL extension implementation to C++.

eval/public/cel_options.cc

@@ -40,7 +40,8 @@ cel::RuntimeOptions ConvertToRuntimeOptions(const InterpreterOptions& options) {
                              options.enable_lazy_bind_initialization,
                              options.max_recursion_depth,
                              options.enable_recursive_tracing,
-                             options.enable_fast_builtins};
+                             options.enable_fast_builtins,
+                             options.locale};
 }
 
 }  // namespace google::api::expr::runtime

eval/public/cel_options.h

@@ -17,6 +17,8 @@
 #ifndef THIRD_PARTY_CEL_CPP_EVAL_PUBLIC_CEL_OPTIONS_H_
 #define THIRD_PARTY_CEL_CPP_EVAL_PUBLIC_CEL_OPTIONS_H_
 
+#include <string>
+
 #include "absl/base/attributes.h"
 #include "runtime/runtime_options.h"
 #include "google/protobuf/arena.h"
@@ -196,6 +198,11 @@ struct InterpreterOptions {
   //
   // Currently applies to !_, @not_strictly_false, _==_, _!=_, @in
   bool enable_fast_builtins = false;
+
+  // The locale to use for string formatting.
+  //
+  // Default is en_US.
+  std::string locale = "en_US";
 };
 // LINT.ThenChange(//depot/google3/runtime/runtime_options.h)
 

extensions/BUILD

@@ -442,6 +442,7 @@ cc_library(
     srcs = ["strings.cc"],
     hdrs = ["strings.h"],
     deps = [
+        ":formatting",
         "//checker:type_checker_builder",
         "//checker/internal:builtins_arena",
         "//common:casting",
@@ -578,3 +579,59 @@ cc_test(
         "@com_google_absl//absl/status:status_matchers",
     ],
 )
+
+cc_library(
+    name = "formatting",
+    srcs = ["formatting.cc"],
+    hdrs = ["formatting.h"],
+    deps = [
+        "//common:value",
+        "//common:value_kind",
+        "//internal:status_macros",
+        "//runtime:function_adapter",
+        "//runtime:function_registry",
+        "//runtime:runtime_options",
+        "@com_google_absl//absl/base:core_headers",
+        "@com_google_absl//absl/container:btree",
+        "@com_google_absl//absl/memory",
+        "@com_google_absl//absl/numeric:bits",
+        "@com_google_absl//absl/status",
+        "@com_google_absl//absl/status:statusor",
+        "@com_google_absl//absl/strings",
+        "@com_google_absl//absl/strings:str_format",
+        "@com_google_absl//absl/strings:string_view",
+        "@com_google_absl//absl/time",
+        "@icu4c",
+    ],
+)
+
+cc_test(
+    name = "formatting_test",
+    srcs = ["formatting_test.cc"],
+    deps = [
+        ":formatting",
+        "//common:allocator",
+        "//common:value",
+        "//extensions/protobuf:runtime_adapter",
+        "//internal:parse_text_proto",
+        "//internal:testing",
+        "//internal:testing_descriptor_pool",
+        "//internal:testing_message_factory",
+        "//parser",
+        "//parser:options",
+        "//runtime",
+        "//runtime:activation",
+        "//runtime:runtime_builder",
+        "//runtime:runtime_options",
+        "//runtime:standard_runtime_builder_factory",
+        "@com_google_absl//absl/container:flat_hash_map",
+        "@com_google_absl//absl/status:status_matchers",
+        "@com_google_absl//absl/strings",
+        "@com_google_absl//absl/strings:str_format",
+        "@com_google_absl//absl/strings:string_view",
+        "@com_google_absl//absl/time",
+        "@com_google_cel_spec//proto/cel/expr:syntax_cc_proto",
+        "@com_google_cel_spec//proto/cel/expr/conformance/proto3:test_all_types_cc_proto",
+        "@com_google_protobuf//:protobuf",
+    ],
+)