From 0559ecb2bb6b93226366e545b7edad15a05029f5 Mon Sep 17 00:00:00 2001
From: Oleg B <code.viator@gmail.com>
Date: Mon, 11 Feb 2019 13:33:22 +0300
Subject: [PATCH] make-structs cmd line option (#15)

* add plugin option make-structs

* fix example

* Update protoc_gen_d/protoc-gen-d.d

Co-Authored-By: deviator <code.viator@gmail.com>

* Update protoc_gen_d/protoc-gen-d.d

Co-Authored-By: deviator <code.viator@gmail.com>

* fix naming
---
 examples/add_person.d       | 12 +++++++++---
 examples/dub.json           |  4 ++--
 protoc_gen_d/protoc-gen-d.d | 22 ++++++++++++++++++----
 3 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/examples/add_person.d b/examples/add_person.d
index 1697432..1fd7dc5 100644
--- a/examples/add_person.d
+++ b/examples/add_person.d
@@ -6,10 +6,16 @@ import std.string;
 import google.protobuf;
 import tutorial.addressbook;
 
+T make(T)()
+{
+    static if (is(T == class)) return new T;
+    else return T.init;
+}
+
 /// This function fills in a Person message based on user input.
 Person promptForAddress()
 {
-    auto person = new Person;
+    auto person = make!Person;
 
     write("Enter person ID number: ");
     readf("%d", &person.id);
@@ -23,7 +29,7 @@ Person promptForAddress()
 
     while (true)
     {
-        auto phoneNumber = new Person.PhoneNumber;
+        auto phoneNumber = make!(Person.PhoneNumber);
         write("Enter a phone number (or leave blank to finish): ");
         phoneNumber.number = readln!string.strip;
         if (phoneNumber.number.empty)
@@ -57,7 +63,7 @@ int main(string[] args)
         return -1;
     }
 
-    auto addressBook = new AddressBook;
+    auto addressBook = make!AddressBook;
     try
     {
         auto input = File(args[1], "rb");
diff --git a/examples/dub.json b/examples/dub.json
index 9f120eb..e74d82d 100644
--- a/examples/dub.json
+++ b/examples/dub.json
@@ -9,7 +9,7 @@
             "sourceFiles": ["tutorial/addressbook.d"],
             "sourcePaths": ["../src"],
             "mainSourceFile": "add_person.d",
-            "preBuildCommands": ["protoc $$PROTO_PATH --plugin=../build/protoc-gen-d --d_out=. addressbook.proto"]
+            "preBuildCommands": ["protoc $$PROTO_PATH --plugin=../build/protoc-gen-d --d_opt=message-as-struct --d_out=. addressbook.proto"]
         },
         {
             "name": "list_people",
@@ -18,7 +18,7 @@
             "sourceFiles": ["tutorial/addressbook.d"],
             "sourcePaths": ["../src"],
             "mainSourceFile": "list_people.d",
-            "preBuildCommands": ["protoc $$PROTO_PATH --plugin=../build/protoc-gen-d --d_out=. addressbook.proto"]
+            "preBuildCommands": ["protoc $$PROTO_PATH --plugin=../build/protoc-gen-d --d_opt=message-as-struct --d_out=. addressbook.proto"]
         },
     ]
 }
diff --git a/protoc_gen_d/protoc-gen-d.d b/protoc_gen_d/protoc-gen-d.d
index d93577c..42c83b2 100644
--- a/protoc_gen_d/protoc-gen-d.d
+++ b/protoc_gen_d/protoc-gen-d.d
@@ -35,14 +35,18 @@ class CodeGeneratorException : Exception
 class CodeGenerator
 {
     private enum indentSize = 4;
+    private bool messageAsStruct = false;
 
     CodeGeneratorResponse handle(CodeGeneratorRequest request)
     {
-        import std.algorithm : filter, map;
+        import std.algorithm : filter, map, canFind, splitter;
         import std.array : array;
         import std.conv : to;
         import std.format : format;
 
+        if (request.parameter.splitter(",").canFind("message-as-struct"))
+            messageAsStruct = true;
+
         if (request.compilerVersion) with (request.compilerVersion)
             protocVersion = format!"%d%03d%03d"(major, minor, patch);
 
@@ -146,9 +150,18 @@ class CodeGenerator
         if (messageType.isMap)
             return "";
 
+        auto indentation = "%*s".format(indent, "");
+
         auto result = appender!string;
-        result ~= "\n%*s%sclass %s\n".format(indent, "", indent > 0 ? "static " : "", messageType.name.escapeKeywords);
-        result ~= "%*s{\n".format(indent, "");
+        result ~= "\n";
+        result ~= indentation;
+        result ~= indent > 0 ? "static " : "";
+        result ~= messageAsStruct ? "struct" : "class";
+        result ~= " ";
+        result ~= messageType.name.escapeKeywords;
+        result ~= "\n";
+        result ~= indentation;
+        result ~= "{\n";
 
         int[] generatedOneofs;
         foreach (field; messageType.fields.sort!((a, b) => a.number < b.number))
@@ -173,7 +186,8 @@ class CodeGenerator
         foreach (enumType; messageType.enumTypes)
             result ~= generateEnum(enumType, indent + indentSize);
 
-        result ~= "%*s}\n".format(indent, "");
+        result ~= indentation;
+        result ~= "}\n";
 
         return result.data;
     }