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>
- Sequential evaluation of lists