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Re: How best to implement a hash table in Mathematica

  • To: mathgroup at smc.vnet.net
  • Subject: [mg125105] Re: How best to implement a hash table in Mathematica
  • From: Szabolcs Horvát <szhorvat at gmail.com>
  • Date: Tue, 21 Feb 2012 06:17:15 -0500 (EST)
  • Delivered-to: l-mathgroup@mail-archive0.wolfram.com
  • References: <jho21j$5sb$1@smc.vnet.net> <jhqmrr$fbq$1@smc.vnet.net> <jhstsv$nk0$1@smc.vnet.net>

On 2/20/2012 9:48 AM, Joseph Gwinn wrote:
>
> The reason to initialize the hashtable in advance is so a later probe to
> an empty table element yields {}, versus repeating the question back.
>
>

I probably don't understand your question completely, but why can't you 
just make definition like

hashtable[_] = {}

?  This will ensure that {} is returned for "undefined" keys.

Also, please avoid using symbols that start with a capital letter. 
HashTable is a built-in symbol and if you define it (as you did in the 
example code you sent), it is likely to break stuff.

-- 
Szabolcs Horvát
Visit Mathematica.SE:  http://mathematica.stackexchange.com/



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