Re: Re: Sequential evaluation of lists

*To*: mathgroup at smc.vnet.net*Subject*: [mg53131] Re: [mg53088] Re: [mg53076] Sequential evaluation of lists*From*: yehuda ben-shimol <benshimo at bgu.ac.il>*Date*: Fri, 24 Dec 2004 05:59:31 -0500 (EST)*References*: <200412220953.EAA04525@smc.vnet.net> <200412231258.HAA21092@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

The evaluation order is an internal property of Mathematica's function. It has strong effect on their efficiency (memory management and the way internal data is stored). However, I think that partial control is available if you Reverse the input before evaluation, say func&/@Reverse[yourInputList] yehuda János wrote: >It would be nice to have all List manipulation functions have an option >Direction->Left or Direction->Right, just as Limit has +1 or -1. I even >would like functional programming functions like Map or Apply have this >option. Any seesaw type operation modeling would greatly benefit from >it and nature has many. > >János >On Dec 22, 2004, at 4:53 AM, Ray Koopman wrote: > > > > > >>When I first started using Mathematica (v2), one of the features that >>I found rather surprising is its sequential evaluation of lists, as in >> >>In[1]:= x = 0; {x++,x++,x++} >>Out[1]= {0,1,2} >> >>I had expected a warning that such code should be avoided because >>it presumed sequential evaluation, which could not be guaranteed, >>and a recommendation to treat list elements as being evaluated in >>parallel -- if not simultaneously then in no particular order. >>However, so far I have found no exception to sequential evaluation >>and no mention of it in any documentation. Have I missed something? >>

**References**:**Sequential evaluation of lists***From:*"Ray Koopman" <koopman@sfu.ca>

**Re: Sequential evaluation of lists***From:*János <janos.lobb@yale.edu>