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Re: Function, Command, Operator, Object...etc.

• To: mathgroup at smc.vnet.net
• Subject: [mg61436] Re: Function, Command, Operator, Object...etc.
• From: albert <awnl at arcor.de>
• Date: Wed, 19 Oct 2005 02:16:15 -0400 (EDT)
• References: <200510160418.AAA22613@smc.vnet.net> <dj27iv$bnn$1@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Chris Chiasson wrote:

> Maybe I am wrong, but pretty much every expression has a head and zero
> or more slots. That's it.
> 
> I wonder if a pattern is an expression...

of course, why not? Everything is an expression (within mathematica). I
think this is somewhere in the documentation. Evaluate the following lines
to become a believer :-)

ToExpression["Pattern[x,Blank[]]"]

FullForm[x_]

Head[x___]

mypattern = x_
newpattern = mypattern /. Verbatim[x_] :> x___
{newpattern}
MatchQ[{}, {newpattern}]
MatchQ[{1,2,3},{newpattern}:>Hold[x]]


albert

• References:
  • Function, Command, Operator, Object...etc.
    • From: "Steven T. Hatton" <hattons@globalsymmetry.com>