The vector of parameter names is matched to the actual parameter values when the fn is called, so it's equivalent to
(let [x val1 y val2] ...) when (hypot val1 val2) is called. -- Fergal Byrne, Brenter IT Author, Real Machine Intelligence with Clortex and NuPIC https://leanpub.com/realsmartmachines Speaking on Clortex and HTM/CLA at euroClojure Krakow, June 2014: http://euroclojure.com/2014/ and at LambdaJam Chicago, July 2014: http://www.lambdajam.com http://inbits.com - Better Living through Thoughtful Technology http://ie.linkedin.com/in/fergbyrne/ - https://github.com/fergalbyrne e:fergalbyrnedub...@gmail.com t:+353 83 4214179 Join the quest for Machine Intelligence at http://numenta.org Formerly of Adnet edi...@adnet.ie http://www.adnet.ie On Wed, Jul 22, 2015 at 1:25 PM, Gary Trakhman <gary.trakh...@gmail.com> wrote: > I am looking at the definition of fn and I can't see where let is used > inside the function definition: > https://github.com/clojure/clojure/blob/master/src/clj/clojure/core.clj#L4335 > I think they're saying the binding forms are equivalent in power > (destructuring), not implementation. > On Wed, Jul 22, 2015 at 8:07 AM Johnny Wong <zhanlandet...@gmail.com> wrote: >> page 27(pdf version): >> " >> >> Local Bindings: let >> >> >> let allows you to define named references that are lexically scoped to >> the extent of the let expression. Said another way, let defines locals. >> ...... >> ... >> >> Note that let is implicitly used anywhere locals are required. In >> particular, fn (and therefore all other function-creation and >> function-definition forms like defn) uses let to bind function parameters >> as locals within the scope of the function being defined. For example, x and >> y in the hypot function above are let-bound by defn. *So, the vector that >> defines the set of bindings for a let scope obeys the same semantics >> whether it is used to define function parameters or an auxiliary local >> binding scope.* >> >> >> *"* >> >> i am confused about the text in red. apparently ,the vector used for >> let locale binding is not the same as the vector used for function >> parameters , for example >> >> >> (defn hypot >> >> [x y] >> >> (let [x2 (* x x) y2 (* y y)] >> >> (Math/sqrt (+ x2 y2))) >> >> ) >> >> >> the second line [x y] vector says the function has two parameter, it >> doesn't mean let x=y, while , the third line ,it means let x2=(* x x), it >> is set value operation. >> >> >> is it a book error ? >> >> -- >> 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. >> > -- > 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. -- 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.
