The lack of default argument values initially annoyed me, but I kind of came to like it. It makes me put more thought into my function interfaces.

In the rare cases I do want a default it's usually reasonable to just add a second function that calls the first with the default value.

I don't end up doing this a lot, but I certainly have in a couple handful of cases. A lot of Go libraries for HTTP related activities do this with the default context. They'll have a function that accepts a context and a function that has the default context.

Example

https://github.com/slack-go/slack/blob/242df4614edb261e5f4f4...

Honestly, with good naming, I think this is just generally more readable and expectable behavior only takes three lines of code.