Can not define two same enum name in the same proto file

[go4awalk]

Version: grpc-protobuf 1.14.0
Language: Java
OS: Windows 7

Steps to reproduce the behavior:
Define the following two enum in the same proto file, both TestEnum1 and TestEnum2 have a enum constant named UNKNOWN.

enum TestEnum1 {
    IDLE = 0;
    RUNNING = 1;
    UNKNOWN = -1;
}

enum TestEnum2 {
    MAN = 0;
    ANIMAL = 1;
    UNKNOWN = -1;
}

What did you expect to see
The proto will be compiled successfully.

What did you see instead?
I got the following compile error:
"UNKNOWN" is already defined in "xxx".

And it's interesting that we can't define two same enum constant in the same proto file, but protobuf will add a UNRECOGNIZED enum constant to every enum in the Java class generated after compiling.

[acozzette]

This behavior is actually expected. The enum values go into the scope enclosing the whole enum definition, so in cases like your example, values in different enums can still conflict with each other. Probably the best way around it is just to put a prefix in front of UNKNOWN, like TEST_ENUM1_UNKNOWN for example.

[go4awalk]

@acozzette
Although this behavior is expected, it's really not friendly to developer. Values in different enums don't conflict with each other in Java.

[TeBoring]

The general proto syntax has to taken all supported languages into account.

[ncioj10]

Isn't it possible to use scoped enums for c++ 11 and implement an option to specify which enums to be used. We mainly use Java and it's seriously utterly stupid that this requires these kinds of hacks.

[j-vizcaino]

Same applies in Go where the enum value gets automatically prefixed with the enum name by the code generator.
Manually adding the enum name again as a prefix in the enum value results in stuttering and is very unpleasant to read and use 😢

[prakhar-ap]

Hi folks,
I was finding the best way to write enum but didn't found any solution what i am looking for.

I need to check that if this enum valid?

enum Scope {
  ...
 _ADMIN = 31;
}

[emeraldhieu]

The design looks odd. Prefixing with the enum name sends me back to the old age of programming.

[sanan-fataliyev]

It is common use case to define UNSPECIFIED/UNKNOWN=0 in enums to avoid undesired defaults, and require explicit values.
Providing syntax to define multiple enum types without isolated scope for their values looks like an incomplete design.

[anthonyalayo]

Is there any plans to fix this? Is there any clean workaround for this in 2024? It really doesn't make any sense.

[hayyaun]

+1

[jotalanusse]

JavaScript projects that use @grpc/proto-loader rely on being able to convert enum values into strings and use them as such. The fact that the current solution requires prefixing every enum value with the name of the enum is ridiculous.

Please fix the current design!

[domeniconappo]

For the series: things you won't find in the README.md.

[ZheruiL]

at least remove the prefix if the prefix has the same name as the enum name please, for example:

enum PhoneType {
  PHONE_TYPE_UNSPECIFIED = 0;
  PHONE_TYPE_MOBILE = 1;
  PHONE_TYPE_HOME = 2;
  PHONE_TYPE_WORK = 3;
}

type PhoneType int32

const (
	PhoneType_PHONE_TYPE_UNSPECIFIED PhoneType = 0
	PhoneType_PHONE_TYPE_MOBILE      PhoneType = 1
	PhoneType_PHONE_TYPE_HOME        PhoneType = 2
	PhoneType_PHONE_TYPE_WORK        PhoneType = 3
)

it repeats PhoneType twice.

can't it be just PhoneType_MOBILE as a result ?

[fastfend]

It looks like after this issue was closed it went directly into "do not elaborate further" trash bin