Implement type() standard function, integrate in planner

common/src/main/java/dev/cel/common/types/BUILD.bazel

@@ -193,10 +193,26 @@ java_library(
     deps = [
         ":type_providers",
         ":types",
+        "@maven//:com_google_errorprone_error_prone_annotations",
         "@maven//:com_google_guava_guava",
     ],
 )
 
+cel_android_library(
+    name = "default_type_provider_android",
+    srcs = [
+        "DefaultTypeProvider.java",
+    ],
+    tags = [
+    ],
+    deps = [
+        ":type_providers_android",
+        ":types_android",
+        "@maven//:com_google_errorprone_error_prone_annotations",
+        "@maven_android//:com_google_guava_guava",
+    ],
+)
+
 cel_android_library(
     name = "cel_types_android",
     srcs = ["CelTypes.java"],

common/src/main/java/dev/cel/common/types/DefaultTypeProvider.java

@@ -16,9 +16,11 @@
 
 import com.google.common.collect.ImmutableCollection;
 import com.google.common.collect.ImmutableMap;
+import com.google.errorprone.annotations.Immutable;
 import java.util.Optional;
 
 /** {@code DefaultTypeProvider} is a registry of common CEL types. */
+@Immutable
 public class DefaultTypeProvider implements CelTypeProvider {
 
   private static final DefaultTypeProvider INSTANCE = new DefaultTypeProvider();
@@ -43,6 +45,7 @@ private DefaultTypeProvider() {
     typeMapBuilder.putAll(SimpleType.TYPE_MAP);
     typeMapBuilder.put("list", ListType.create(SimpleType.DYN));
     typeMapBuilder.put("map", MapType.create(SimpleType.DYN, SimpleType.DYN));
+    typeMapBuilder.put("type", TypeType.create(SimpleType.DYN));
     typeMapBuilder.put(
         "optional_type",
         // TODO: Move to CelOptionalLibrary and register it on demand

common/types/BUILD.bazel

@@ -81,3 +81,8 @@ cel_android_library(
     name = "cel_proto_types_android",
     exports = ["//common/src/main/java/dev/cel/common/types:cel_proto_types_android"],
 )
+
+cel_android_library(
+    name = "default_type_provider_android",
+    exports = ["//common/src/main/java/dev/cel/common/types:default_type_provider_android"],
+)

runtime/BUILD.bazel

@@ -9,14 +9,31 @@ package(
 java_library(
     name = "runtime",
     exports = [
+        ":descriptor_message_provider",
         ":evaluation_exception",
+        ":function_overload",
         ":late_function_binding",
         ":metadata",
+        ":runtime_factory",
+        ":runtime_legacy_impl",
+        ":variable_resolver",
         "//runtime/src/main/java/dev/cel/runtime",
-        "//runtime/src/main/java/dev/cel/runtime:descriptor_message_provider",
-        "//runtime/src/main/java/dev/cel/runtime:function_overload",
         "//runtime/src/main/java/dev/cel/runtime:runtime_type_provider",
-        "//runtime/src/main/java/dev/cel/runtime:variable_resolver",
+    ],
+)
+
+java_library(
+    name = "runtime_factory",
+    exports = [
+        "//runtime/src/main/java/dev/cel/runtime:runtime_factory",
+    ],
+)
+
+java_library(
+    name = "runtime_legacy_impl",
+    visibility = ["//:internal"],
+    exports = [
+        "//runtime/src/main/java/dev/cel/runtime:runtime_legacy_impl",
     ],
 )
 
@@ -28,6 +45,14 @@ java_library(
     ],
 )
 
+cel_android_library(
+    name = "dispatcher_android",
+    visibility = ["//:internal"],
+    exports = [
+        "//runtime/src/main/java/dev/cel/runtime:dispatcher_android",
+    ],
+)
+
 java_library(
     name = "standard_functions",
     exports = [
@@ -43,6 +68,14 @@ java_library(
     ],
 )
 
+cel_android_library(
+    name = "activation_android",
+    visibility = ["//:internal"],
+    exports = [
+        "//runtime/src/main/java/dev/cel/runtime:activation_android",
+    ],
+)
+
 java_library(
     name = "proto_message_activation_factory",
     visibility = ["//:internal"],
@@ -79,6 +112,7 @@ cel_android_library(
 
 java_library(
     name = "evaluation_exception_builder",
+    # used_by_android
     exports = ["//runtime/src/main/java/dev/cel/runtime:evaluation_exception_builder"],
 )
 
@@ -112,6 +146,12 @@ java_library(
     exports = ["//runtime/src/main/java/dev/cel/runtime:interpretable"],
 )
 
+cel_android_library(
+    name = "interpretable_android",
+    visibility = ["//:internal"],
+    exports = ["//runtime/src/main/java/dev/cel/runtime:interpretable_android"],
+)
+
 java_library(
     name = "runtime_helpers",
     visibility = ["//:internal"],
@@ -154,6 +194,18 @@ java_library(
     exports = ["//runtime/src/main/java/dev/cel/runtime:type_resolver"],
 )
 
+cel_android_library(
+    name = "type_resolver_android",
+    visibility = ["//:internal"],
+    exports = ["//runtime/src/main/java/dev/cel/runtime:type_resolver_android"],
+)
+
+java_library(
+    name = "descriptor_type_resolver",
+    visibility = ["//:internal"],
+    exports = ["//runtime/src/main/java/dev/cel/runtime:descriptor_type_resolver"],
+)
+
 java_library(
     name = "unknown_attributes",
     exports = ["//runtime/src/main/java/dev/cel/runtime:unknown_attributes"],
@@ -253,23 +305,35 @@ cel_android_library(
 
 java_library(
     name = "metadata",
+    # used_by_android
     visibility = ["//:internal"],
     exports = ["//runtime/src/main/java/dev/cel/runtime:metadata"],
 )
 
+java_library(
+    name = "variable_resolver",
+    # used_by_android
+    exports = ["//runtime/src/main/java/dev/cel/runtime:variable_resolver"],
+)
+
 java_library(
     name = "concatenated_list_view",
+    # used_by_android
     visibility = ["//:internal"],
     exports = [
         "//runtime/src/main/java/dev/cel/runtime:concatenated_list_view",
     ],
 )
 
 java_library(
-    name = "variable_resolver",
-    exports = [
-        "//runtime/src/main/java/dev/cel/runtime:variable_resolver",
-    ],
+    name = "function_overload",
+    exports = ["//runtime/src/main/java/dev/cel/runtime:function_overload"],
+)
+
+java_library(
+    name = "descriptor_message_provider",
+    visibility = ["//:internal"],
+    exports = ["//runtime/src/main/java/dev/cel/runtime:descriptor_message_provider"],
 )
 
 java_library(