Re: List to Expression

*To*: mathgroup at smc.vnet.net*Subject*: [mg106078] Re: [mg106055] List to Expression*From*: DrMajorBob <btreat1 at austin.rr.com>*Date*: Fri, 1 Jan 2010 05:32:36 -0500 (EST)*References*: <200912310817.DAA24881@smc.vnet.net>*Reply-to*: drmajorbob at yahoo.com

Close, but no cigar: {a, {b, {c, d}}} /. List -> Compose a[b[c[d]]] ditto: expr = {a, {b, {c, d}}}; k = Depth@expr; Replace[expr, List -> Compose, {0, k - 2}, Heads -> True] Perfect: expr //. {{a_, b_List} :> a[b], List -> Sequence} a[b[c, d]] Bobby On Thu, 31 Dec 2009 02:17:33 -0600, Spell <l_sharonj at hotmail.com> wrote: > Hellp, > > I am having trouble converting a list into an "expression". For example > suppose I have the following list expression. > l = {a, {b, {c, d}}} > > When I evaluate the FullForm version, I get an output with List as the > Head. > List[a,List[b,List[c,d]]] > > But, I would like the following output instead: a[b[c,d]], wondering how > this would be accomplised. > > PS: > Essentially, I have a FunctionSet with various functions in it. And > would like to generate a tree of functions, from the FunctionSet. So, > say I have functions from a to d in the set. Then, I can generate > something like: d[a[b], c[d[a[b]]]. > > Thank you. > -- DrMajorBob at yahoo.com