Fix compile issues in Google/NaturalLanguage (#643)

Motivation:

The NaturalLanguage example did not compile because of breaking API
changes between pre-release version.

Modifications:

Fix compilation issues.

Result:

NaturalLanguage example compiles.

Author: glbrntt

Examples/Google/NaturalLanguage/Makefile

@@ -3,7 +3,7 @@ all:
 	swift build -c release
 	cp .build/release/NaturalLanguage .
 
-clean :
+clean:
 	rm -rf Packages googleapis .build
 	rm -f Package.pins NaturalLanguage Sources/*.pb.swift Sources/*.grpc.swift google.json
 	rm -rf Package.resolved

Examples/Google/NaturalLanguage/Package.resolved

@@ -20,16 +20,18 @@ let package = Package(
   name: "NaturalLanguage",
   dependencies: [
     .package(url: "../../..", .branch("HEAD")),
-    .package(url: "https://github.com/apple/swift-protobuf.git", from: "1.0.2"),
-    .package(url: "https://github.com/kylef/Commander.git", from: "0.8.0"),
+    .package(url: "https://github.com/apple/swift-protobuf.git", from: "1.7.0"),
     .package(url: "https://github.com/googleapis/google-auth-library-swift.git", from: "0.5.0")
   ],
   targets: [
-    .target(name: "NaturalLanguage",
-            dependencies: [
-              "GRPC",
-              "SwiftProtobuf",
-              "Commander",
-              "OAuth2"],
-            path: "Sources")
-  ])
+    .target(
+      name: "NaturalLanguage",
+      dependencies: [
+        "GRPC",
+        "SwiftProtobuf",
+        "OAuth2"
+      ],
+      path: "Sources"
+    )
+  ]
+)

Examples/Google/NaturalLanguage/Package.swift

@@ -15,14 +15,18 @@ if [ ! -d "googleapis" ]; then
 fi
 
 protoc \
- 	google/cloud/language/v1/language_service.proto \
+	google/cloud/language/v1/language_service.proto \
 	google/api/annotations.proto \
 	google/api/http.proto \
 	google/protobuf/descriptor.proto \
- 	-Igoogleapis \
+	-Igoogleapis \
 	-I../common/include \
 	--swift_out=googleapis \
 	--grpc-swift_out=googleapis
 
-# move Swift files to the Sources directory
-find googleapis -name "*.swift" -exec mv {} Sources \;
+# Move Swift files to the Sources directory. descriptor.pb.swift is provided
+# with SwiftProtobuf (from 1.7.0).
+find googleapis \
+  -name "*.swift" \
+  ! -name "descriptor.pb.swift" \
+  -exec mv {} Sources \;

Examples/Google/NaturalLanguage/RUNME

@@ -0,0 +1,70 @@
+// DO NOT EDIT.
+//
+// Generated by the Swift generator plugin for the protocol buffer compiler.
+// Source: google/api/annotations.proto
+//
+// For information on using the generated types, please see the documentation:
+//   https://github.com/apple/swift-protobuf/
+
+// Copyright (c) 2015, Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import Foundation
+import SwiftProtobuf
+
+// If the compiler emits an error on this type, it is because this file
+// was generated by a version of the `protoc` Swift plug-in that is
+// incompatible with the version of SwiftProtobuf to which you are linking.
+// Please ensure that your are building against the same version of the API
+// that was used to generate this file.
+fileprivate struct _GeneratedWithProtocGenSwiftVersion: SwiftProtobuf.ProtobufAPIVersionCheck {
+  struct _2: SwiftProtobuf.ProtobufAPIVersion_2 {}
+  typealias Version = _2
+}
+
+// MARK: - Extension support defined in annotations.proto.
+
+extension SwiftProtobuf.Google_Protobuf_MethodOptions {
+
+  /// See `HttpRule`.
+  var Google_Api_http: Google_Api_HttpRule {
+    get {return getExtensionValue(ext: Google_Api_Extensions_http) ?? Google_Api_HttpRule()}
+    set {setExtensionValue(ext: Google_Api_Extensions_http, value: newValue)}
+  }
+  /// Returns true if extension `Google_Api_Extensions_http`
+  /// has been explicitly set.
+  var hasGoogle_Api_http: Bool {
+    return hasExtensionValue(ext: Google_Api_Extensions_http)
+  }
+  /// Clears the value of extension `Google_Api_Extensions_http`.
+  /// Subsequent reads from it will return its default value.
+  mutating func clearGoogle_Api_http() {
+    clearExtensionValue(ext: Google_Api_Extensions_http)
+  }
+
+}
+
+/// A `SwiftProtobuf.SimpleExtensionMap` that includes all of the extensions defined by
+/// this .proto file. It can be used any place an `SwiftProtobuf.ExtensionMap` is needed
+/// in parsing, or it can be combined with other `SwiftProtobuf.SimpleExtensionMap`s to create
+/// a larger `SwiftProtobuf.SimpleExtensionMap`.
+let Google_Api_Annotations_Extensions: SwiftProtobuf.SimpleExtensionMap = [
+  Google_Api_Extensions_http
+]
+
+/// See `HttpRule`.
+let Google_Api_Extensions_http = SwiftProtobuf.MessageExtension<SwiftProtobuf.OptionalMessageExtensionField<Google_Api_HttpRule>, SwiftProtobuf.Google_Protobuf_MethodOptions>(
+  _protobuf_fieldNumber: 72295728,
+  fieldName: "google.api.http"
+)