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> Obviously Go code shown here doesn't show string enums. It's an integer enum with function that converts integer value to the string representation (by implem

> Obviously Go code shown here doesn't show string enums. It's an integer enum with function that converts integer value to the string representation (by implementing Stringer interface). Which makes total sense (not every int enum needs String conversion). Considering your robust defence of Go, maybe you can demonstrate the simplicity of Go's string enums? > I assume your Java example has some magic (aka conventions) in how to convert values into string. Without reading Java manuals, how do I know what's the magic's conversion function? There is no magic - .toString() produces an equivalent string. The point is to keep simple things simple - most of the time, the enum value and its string representation is same and the snippet in my previous post automatically gets us there. > With single words it's usually easy, but try two words "LeapYear" or text with non-Unicode chars - how the magic will work then? Go tries to minimize amount of hidden magic. Thanks for acknowledging that it is atleast easy in Java for single words. Words with spaces or unicode (I think thats what you meant when you said non-Unicode) isn't terrible either: enum Season { SUMMER("S U M M E R "), AUTUMN("A U T M N "), WINTER("W I N T E R "), SPRING( "S P R I N G "); private String value; private Season(String value) { this.value = value; } public String toString() { return this.value; } } I had to introduce a variable and couple of one-line methods which isn't super simple but still a win over a switch statement that requires listing out every representation. For shits and giggles, this is how I can enumerate over the enum values in Java: for (Season s : Season.values()) { System.out.println(s); } Feel free to show how you would do it in Golang with iota magic... PS: seems like the unicode strings that I pasted didn't carry over to HNs code snippet. The same is available on pastebin: https://pastebin.com/Yw0jyGDE https://pastebin.com/Yw0jyGDE

divan 4y ago
I think people mean different things by enums. Is it just a set of constants of a given type or a sum type (aka variant type)? Go doesn't have sum types at all. `iota` is just a syntax sugar for enumerating integer constants/variables. But as you're talking about string enums, the Go equivalent would be: type Season string const ( Summer Season = "Summer" Autumn = "Autumn" Winter = "Winter" Spring = "Spring" ) But, again, that's not a variant type, so you can still assign a different value to the variable of the type Season. Which is rarely a problem in practice (there are other ways to validate data rather than by type system constraints). So just to clarify, many of the use cases for enumerated values do not need string representation. Go has no magical way to translate varibale/const name into the string.
- noisy_boy 4y ago
  By enum I mean this: > An enum type is a special data type that enables for a variable to be a set of predefined constants. The variable must be equal to one of the values that have been predefined for it. [0] > Is it just a set of constants of a given type or a sum type (aka variant type)? So by above definition, it is a set of predefined constants. > But, again, that's not a variant type, so you can still assign a different value to the variable of the type Season. Which kinda defeats the purpose doesn't it? > Which is rarely a problem in practice (there are other ways to validate data rather than by type system constraints). I'm not sure I agree that it is a rare problem - if I can't rely on the type system to do a check that something belongs to a set of predefined constants, that is a pretty basic part missing. Of course there would be other ways but being able to lean on the type system would be a pretty reasonable expectation. > So just to clarify, many of the use cases for enumerated values do not need string representation. Sure - just like many of the use cases do require string representation. It is not unreasonable to expect that enumerations as defined above should be able handle cases that do and don't require string representation. > Go has no magical way to translate varibale/const name into the string. You keep using this word magical when it comes to addressing the limitations of the language. Java isn't doing "magic" when it is able to return a string representation of the enum value - it is part of the language. Credit where credit is due etc. [0]: https://docs.oracle.com/javase/tutorial/java/javaOO/enum.html https://docs.oracle.com/javase/tutorial/java/javaOO/enum.htm...
  - divan 4y ago
    > Which kinda defeats the purpose doesn't it? Have you actually tried it or you just ranting that Go is not Java? Take `time.Weekday` type, for example from Go stdlib. It's a typical use of kinda enums in Go. [1] It serves the purpose to effectively use Weekday whenever it's needed – in literals, in tests, in debug output, etc. Internally it's just an int, but for humans it's better to work with named predefined constants. Instead of creating yet another language feature that will automagically (yes, I keep repeating it, because it matters) convert variable names into strings, Weekday type leverages other Go features to achieve it in a more appropriate way, implementing proper string conversion for long and short forms for English and leaving room for proper i18n handling (it's still a named int constant). [2] Having it as a separate named type makes it handy for proper type checking (so you can't pass some integer with incorrect value to the function expecting time.Weekday). And now you're saying that it's all useless and wrong, because compiler is not enforcing range of values that varaible of this type can have. But I tell you that it's useful and helping code readability enormously even without being a sum type. And I hope it's clear that when you switch to another language, the worst thing you can do is to complain that it's different from your previous favourite language. You not just switching use another syntax, but you changing the ways to do things and even philosophy. It's like moving to another country - you not just changing a language, you switching to a different culture and economy. You adopt their social norms, follow the rules of that country and pay taxes even if in your country it was all different. So yeah, in Go there are no sum types aka enums. And you know what, Go is extremely effective at what it was designed to despite of this. And "Go enums" work just fine, until they may be improved in the future when community is in consensus on how implement it, respecting backward-compatibility rule. [1] https://cs.opensource.google/go/go/+/refs/tags/go1.18.2:src/time/time.go;drc=90462dfc3aa99649de90bb587af56a9cb0214665;l=308 https://cs.opensource.google/go/go/+/refs/tags/go1.18.2:src/... [2] https://cs.opensource.google/go/go/+/refs/tags/go1.18.2:src/time/format.go;drc=8a56c7742d96c8ef8e8dcecaf3d1c0e9f022f708;l=316 https://cs.opensource.google/go/go/+/refs/tags/go1.18.2:src/...

divan 4y ago

I think people mean different things by enums. Is it just a set of constants of a given type or a sum type (aka variant type)? Go doesn't have sum types at all. `iota` is just a syntax sugar for enumerating integer constants/variables. But as you're talking about string enums, the Go equivalent would be: type Season string const ( Summer Season = "Summer" Autumn = "Autumn" Winter = "Winter" Spring = "Spring" ) But, again, that's not a variant type, so you can still assign a different value to the variable of the type Season. Which is rarely a problem in practice (there are other ways to validate data rather than by type system constraints). So just to clarify, many of the use cases for enumerated values do not need string representation. Go has no magical way to translate varibale/const name into the string.

noisy_boy 4y ago
By enum I mean this: > An enum type is a special data type that enables for a variable to be a set of predefined constants. The variable must be equal to one of the values that have been predefined for it. [0] > Is it just a set of constants of a given type or a sum type (aka variant type)? So by above definition, it is a set of predefined constants. > But, again, that's not a variant type, so you can still assign a different value to the variable of the type Season. Which kinda defeats the purpose doesn't it? > Which is rarely a problem in practice (there are other ways to validate data rather than by type system constraints). I'm not sure I agree that it is a rare problem - if I can't rely on the type system to do a check that something belongs to a set of predefined constants, that is a pretty basic part missing. Of course there would be other ways but being able to lean on the type system would be a pretty reasonable expectation. > So just to clarify, many of the use cases for enumerated values do not need string representation. Sure - just like many of the use cases do require string representation. It is not unreasonable to expect that enumerations as defined above should be able handle cases that do and don't require string representation. > Go has no magical way to translate varibale/const name into the string. You keep using this word magical when it comes to addressing the limitations of the language. Java isn't doing "magic" when it is able to return a string representation of the enum value - it is part of the language. Credit where credit is due etc. [0]: https://docs.oracle.com/javase/tutorial/java/javaOO/enum.html https://docs.oracle.com/javase/tutorial/java/javaOO/enum.htm...
- divan 4y ago
  > Which kinda defeats the purpose doesn't it? Have you actually tried it or you just ranting that Go is not Java? Take `time.Weekday` type, for example from Go stdlib. It's a typical use of kinda enums in Go. [1] It serves the purpose to effectively use Weekday whenever it's needed – in literals, in tests, in debug output, etc. Internally it's just an int, but for humans it's better to work with named predefined constants. Instead of creating yet another language feature that will automagically (yes, I keep repeating it, because it matters) convert variable names into strings, Weekday type leverages other Go features to achieve it in a more appropriate way, implementing proper string conversion for long and short forms for English and leaving room for proper i18n handling (it's still a named int constant). [2] Having it as a separate named type makes it handy for proper type checking (so you can't pass some integer with incorrect value to the function expecting time.Weekday). And now you're saying that it's all useless and wrong, because compiler is not enforcing range of values that varaible of this type can have. But I tell you that it's useful and helping code readability enormously even without being a sum type. And I hope it's clear that when you switch to another language, the worst thing you can do is to complain that it's different from your previous favourite language. You not just switching use another syntax, but you changing the ways to do things and even philosophy. It's like moving to another country - you not just changing a language, you switching to a different culture and economy. You adopt their social norms, follow the rules of that country and pay taxes even if in your country it was all different. So yeah, in Go there are no sum types aka enums. And you know what, Go is extremely effective at what it was designed to despite of this. And "Go enums" work just fine, until they may be improved in the future when community is in consensus on how implement it, respecting backward-compatibility rule. [1] https://cs.opensource.google/go/go/+/refs/tags/go1.18.2:src/time/time.go;drc=90462dfc3aa99649de90bb587af56a9cb0214665;l=308 https://cs.opensource.google/go/go/+/refs/tags/go1.18.2:src/... [2] https://cs.opensource.google/go/go/+/refs/tags/go1.18.2:src/time/format.go;drc=8a56c7742d96c8ef8e8dcecaf3d1c0e9f022f708;l=316 https://cs.opensource.google/go/go/+/refs/tags/go1.18.2:src/...