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Re: how to avoid this evaluation?

  • To: mathgroup at smc.vnet.net
  • Subject: [mg37622] Re: how to avoid this evaluation?
  • From: arrayan137 at yahoo.com (elcofres)
  • Date: Wed, 6 Nov 2002 06:58:16 -0500 (EST)
  • References: <ap5g9b$4l1$1@smc.vnet.net> <apv60v$r3t$1@smc.vnet.net>
  • Sender: owner-wri-mathgroup at wolfram.com

Thanks a lot, OwnValues did what I wanted,
Cheers,
Elcofres

Jens-Peer Kuska <kuska at informatik.uni-leipzig.de> wrote in message news:<apv60v$r3t$1 at smc.vnet.net>...
> Hi,
> 
> a=x^2 
> 
> is *not* a function, it is a value.
> The value of a symbol is stored in
> OwnValue[someSymbol]
> 
> For a you will get
> 
> {HoldPattern[a] :> x^2}
> 
> and you have to work with this form
> and not with an assigment a=x^2, i.e.
> 
> SetAttributes[OwnValueString, HoldAll]
> 
> OwnValueString[from_Symbol] :=
>     Module[{own, st},
>     own = OwnValues[Unevaluated[from]] ;
>     st = ToString[Unevaluated[from]];
>     StringReplace[
>       ToString[own /. HoldPattern[from] :> st /. 
>           Verbatim[HoldPattern][any_] :> any, InputForm], {":>" -> "=", 
>         "\"" -> ""}]
>     ]
> 
> will return the string "{a=x^2}"
> 
> Regards
>   Jens
>


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