Re: Implementing a array assignment for custom data structure
- To: mathgroup at smc.vnet.net
- Subject: [mg88924] Re: Implementing a array assignment for custom data structure
- From: Bill Rowe <readnews at sbcglobal.net>
- Date: Wed, 21 May 2008 14:51:43 -0400 (EDT)
On 5/20/08 at 2:25 AM, smangano at into-technology.com (Salvatore Mangano) wrote: >Lists support a convenient syntax for element assignment: >a[[i]]=v >Of course this syntax is syntactic sugar for: >Set[Part[a, i], v] >SparseArray's have a different structure than lists but still >support the same syntax. >This leads me to believe that I should be able to implement a custom >type (akin to SparseArray) that also allows this syntax (possibly >using UpValues) but for the life of me I can't see how to accomplish >this. It would be helpful if you provided a specific example of what you want to accomplish. But having said that, I don't know that the existing syntax won't work for you. Pretty much any thing in Mathematica can be viewed as having parts. For example: In:= f = x + y + z; f[] = 3; f Out= x+z+3 The only real difficulty with more complex expressions is identifying the part level specification needed to change the portion of the expression you want changed.