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Re: Help with HoldAll needed

• To: mathgroup at smc.vnet.net
• Subject: [mg100900] Re: Help with HoldAll needed
• From: Szabolcs Horvát <szhorvat at gmail.com>
• Date: Thu, 18 Jun 2009 04:49:49 -0400 (EDT)
• References: <h1aaej$8k1$1@smc.vnet.net>

Erich Neuwirth wrote:
> I define
> 
> MyFun[x_]:=Unevaluated[x]
> SetAttributes[MyFun,HoldAllComplete]
> 
> 
> MyFun[2 = 3]
> still evaluated the argument and of course produces an error
> I would like to get the unevaluated expression to be able
> to separate the first argument.
> 
> In fact, I would like MyFun to be a macro which allows me
> to play list processing games with the arguments.
> 
> How can this be accomplished?
> 

Get the first one like this:

MyFun[x_] := First[Unevaluated[x]]
SetAttributes[MyFun, HoldAllComplete]