The odd thing is that Civet includes both do expressions and everything is an expression. I'd be happy with either, but both seems like a bad idea.

Do blocks in Civet are mainly to provide shielded scopes (with local declarations). They're currently also necessary to handle declarations (const/let) in the middle of expressions, but hopefully they won't be necessary eventually - only when the user wants to shield scopes. They also have useful forms like `async do` that let you build Promises using await-style code.