Pitch: Multi-statement if/switch/do expressions

[tera]

@Jon_Shier

So I guess the question is, are if / switch expressions more like functions / closures or more like their statement counterparts?

Obviously if/switch expressions are more like statements than functions/closures:

• no "in"
• no closure / capture list
• can't assign the "uncalled form" to a variable, pass that variable around and call that variable later on
• can't have a return (at least in a "single statement" if expression) while there is no problem of having "return" in a single statement function/closure.)
• no "non trailing closure" form:

    let x = if (true, then: {1}) // 🛑
    let x = if (true, then: {1}, else: {2}) // 🛑

@Jon_Shier

But returning through expressions is exactly what was initially proposed in SE-380 and was discarded precisely because it is confusing

Thanks for the reminder! Reviewing that thread I found that using "return" to mean "expression value" was also regarded as confusing (see discussion for Option #1 linked below).

This, this and this post are particularly interesting. As a compromise solution I like (Option #5), makes sense (bare last expression in if/switch statements, explicit return in functions/closures).