Jan Mercl於 2017年12月31日星期日 UTC+8下午8時05分07秒寫道： > > On Sun, Dec 31, 2017 at 12:48 PM dc0d <kaveh.sh...@gmail.com <javascript:>> > wrote: > > > Indeed everything works according to the specs. That is what is being > questioned (the specs). > > Well, questioning the specification and expecting unspecified behavior > seems like two different things. > > > This behavior for case clause of select statements have different > semantics than case clause of switch statement. > > > > While the latter gets evaluated lazily (short circuited), the former > gets evaluated eagerly - inconsistent semantics for looking-the-same syntax. > > I disagree. A && B does not look-the-same to me compared to A <- B. > Actually, I see nothing in common. One is an expression, the other is a > statement, etc. > > > Here all the values will get prepared first, whether or not they are > going to be used. And only after this step, the select statement would > check if a channel is nil or not. >
Nope, a select statement never check if a channel is nil or not. It checks about blocking and a nil channel never blocks (no matter in or out a select statement). > > That's a fundamentally important property of the select statement. > > > While it should be other way around. First the select statement should > check if a participant channel is nil. And only when a channel is not nil, > the payload should get evaluated. > > That would ruin _everything_. The very purpose of the select statement is > to _proceed_ the communication _as soon as possible_. If the select will > first detect a ready-to-send channel and only after that evaluate the send > value, evaluation of it may block! The whole concept then collapses > immediately. > > > This semantic works in reverse. > > I disagree. > > -- > > -j > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
