On 25 December 2016 at 10:30, Paulus Esterhazy <pesterh...@gmail.com> wrote:
> The following fn names in clojure.core contain an exclamation mark: > > "vswap!" "vreset!" "set-error-mode!" "set-agent-send-executor!" > "disj!" "conj!" "pop!" "compare-and-set!" "reset-meta!" > "set-error-handler!" "set-agent-send-off-executor!" "dissoc!" "assoc!" > "reset!" "alter-meta!" "persistent!" "run!" "set-validator!" "swap!" > "volatile!" "io!" > > What these functions have in common is that they do something > side-effectful, i.e. they do something over and above returning a > value. Well, yes, but they're also unsafe to run in an STM transaction, except potentially for run!. I think that's the convention followed by many in the > community, although it's not a perfect convention -- there are many > side-effecting functions in core without exclamation marks (print, > require, ns-unmap). > require and ns-unmap are side-effecting, but idempotent, meaning that they're safe to run in a transaction. Functions that reference I/O like print or slurp are of course obviously unsafe, and in those cases maybe an exclamation mark was considered redundant. But I guess the answer is that there's no fixed convention for ending a function with an exclamation mark. The Clojure Style Guide suggests exclamation marks should be for functions that are unsafe to use in STM transactions, and I thought that stemmed from their usage in clojure.core, but maybe the meaning is much looser than that. - James -- 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.
