clear, thanks for your reply, i am new clojure learner , i am trying to fully understand the book,
On Wednesday, July 22, 2015 at 11:48:06 PM UTC+8, Fergal Byrne wrote: > > 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:fergalb...@gmail.com <javascript:> t:+353 83 4214179 > Join the quest for Machine Intelligence at http://numenta.org > Formerly of Adnet edi...@adnet.ie <javascript:> http://www.adnet.ie > > > On Wed, Jul 22, 2015 at 1:25 PM, Gary Trakhman <gary.t...@gmail.com > <javascript:>> 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 <zhanla...@gmail.com >> <javascript:>> 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 clo...@googlegroups.com >>> <javascript:> >>> Note that posts from new members are moderated - please be patient with >>> your first post. >>> To unsubscribe from this group, send email to >>> clojure+u...@googlegroups.com <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 clojure+u...@googlegroups.com <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 clo...@googlegroups.com >> <javascript:> >> Note that posts from new members are moderated - please be patient with >> your first post. >> To unsubscribe from this group, send email to >> clojure+u...@googlegroups.com <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 clojure+u...@googlegroups.com <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 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.
