[jamesfisher]

Why is this "tag" system considered a good feature? It seems so arbitrary. It's used exclusively for reflective logic which should instead be done at compile-time via a macro system or a system like Template Haskell, which would generate instances like `ToJson`/`FromJson` for a given struct. As the article mentions, Go tags are similar to Java annotations: a mis-feature motivated by the absence of a macro system.

[skybrian]

You're right that reflection and compile time code generation are somewhat "dual" in the sense that you can often implement a feature using one or the other.

But that doesn't mean everyone should make the same choice. Go doesn't have macros or templates. It would make the language much larger and many Go development tools would have to be modified to deal with the complexity. This is a minimal language tweak that was far easier to implement, and devtools that don't care about tags can ignore them.

[veeti]

Java annotations can be processed during compilation.