Re: can one make local symbol in a pure function?

*To*: mathgroup at smc.vnet.net*Subject*: [mg127386] Re: can one make local symbol in a pure function?*From*: Bob Hanlon <hanlonr357 at gmail.com>*Date*: Fri, 20 Jul 2012 23:41:40 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <20120720075152.D7B14688F@smc.vnet.net>

Clear[f, x] f[x_] := Module[{a = 2}, x^a] lst = Range[5]; f /@ lst {1, 4, 9, 16, 25} Function[{x}, Module[{a = 2}, x^a]] /@ lst {1, 4, 9, 16, 25} Module[{a = 2}, #^a] & /@ lst {1, 4, 9, 16, 25} With[{a = 2}, #^a & /@ lst] {1, 4, 9, 16, 25} Bob Hanlon On Fri, Jul 20, 2012 at 3:51 AM, Nasser M. Abbasi <nma at 12000.org> wrote: > > I was learning a bit about pure functions. > Suppose we have this toy example: > > ----------------- > Clear[f, x] > f[x_] := Module[{a = 2}, x^a] > lst = {1, 2, 3}; > Map[f[#] &, lst] > ------------------- > > ---> {1, 4, 9} > > Now I'd like to define the pure function > in-line, using the Function[] syntax, but > at the same time be able to make a local symbol > 'a' like I did when using Module. But the > syntax does not allow one to do that. There is > no place to define it: > > ------------------ > lst = {1, 2, 3}; > Map[Function[{x}, x^2], lst] > ---------------- > > ---> {1, 4, 9} > > So if someone wants to make a temporary symbol to use > for temporary calculation inside the pure function, like > 'a' in this example, and at the same time not have it be global > symbol, then one must use a Module? I can write > > --------------------- > lst = {1, 2, 3}; > Map[Function[{x}, a=2; x^a], lst] > ---------------------- > > But now 'a' is global, while when using Module it > was local. > > Any way to make local symbols in a pure function like > with Module? > > thanks, > --Nasser >

**References**:**can one make local symbol in a pure function?***From:*"Nasser M. Abbasi" <nma@12000.org>