I think the point is to get nil if x does not satisfy some predicate. The best option would depend on the context in which these expressions are used, but one option would be to write your predicates to return the input as the truthy value (and nil otherwise).
On Friday, 24 October 2014, Laurens Van Houtven <[email protected]> wrote: > Hi Sam, > > > I’m not sure I understand. If not for sequences, then what for? `(if (pred > x) x)` looks like it’s missing an else-clause; so I don’t know what happens > when (not (pred x)). > > From the rest of your e-mail it sounds a little bit like you might want > (get m x x)? (i.e. get me x if x isn’t in m; otherwise give me the value > mapped to x in m). > > > hth > lvh > > > On 24 Oct 2014, at 06:06, Sam Raker <[email protected] <javascript:;>> > wrote: > > > Is there anything simpler/more idiomatic than `(if (pred x) x)`? What I > really want is something better than `(if (= (get a-map a-key) a-val) > a-map)`/`(if (= (get-in a-map some-keys) a-val) a-map)`, but that might be > too specific to have been 'cached' somewhere. > > > > -- > > You received this message because you are subscribed to the Google > > Groups "Clojure" group. > > To post to this group, send email to [email protected] > <javascript:;> > > Note that posts from new members are moderated - please be patient with > your first post. > > To unsubscribe from this group, send email to > > [email protected] <javascript:;> > > 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 [email protected] <javascript:;>. > > For more options, visit https://groups.google.com/d/optout. > > -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to [email protected] Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to [email protected] 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 [email protected]. For more options, visit https://groups.google.com/d/optout.
