On Sunday, October 5, 2014 12:51:04 AM UTC-4, Nahuel Greco wrote: > > I was thinking in a single-consumer scenario with a buffered chan, in > which you want to check if you can consume the value before effectively > consuming it. As you said, a peek operation has no sense if the channel has > multiple consumers. >
And if you can't consume the value, then what? Nothing ever does, and that channel becomes useless? Actually the only "peek" operation that to me makes much sense would be a (take-if pred chan) or something similar, which atomically tests the next value with pred and consumes it or not, so, it can't be consumed elsewhere between the pred test and optional consumption here. And if not consumed, two behaviors both occur to me as possible -- return nil or some other sentinel value for "do not want" or block until the unwanted object is consumed by someone else and then test the next item, etc.; at which point you've got four versions of take-if you'd want, the inside-go and outside-go versions cross product with the two when-not-wanted behaviors. At that point, you'd probably be better off just writing a consumer that splits off the pred-matching items into one out channel and feeds everything else into a second channel, with your original consumer taking from the first of these and the others taking from the second. That gets you the block until version of the behavior. The other version can be had by making the pred-using consumer the sole consumer of the in channel, which takes a value, applies pred, and branches, on the "want" branch doing whatever and on the "do not want" branch putting the value onto an out channel that feeds the other consumers before taking its own "do not want" actions. -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
