MathGroup Archive: April 2012 [00061]

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Pattern Syntax for Alternate Heads with Default Value

To: mathgroup at smc.vnet.net
Subject: [mg125818] Pattern Syntax for Alternate Heads with Default Value
From: Ben <benp84 at gmail.com>
Date: Wed, 4 Apr 2012 04:27:25 -0400 (EDT)
Delivered-to: l-mathgroup@mail-archive0.wolfram.com

I'm trying to build a unary function which accepts only arguments with
two possible heads and has a default value.  That is, something like
the following, except that this doesn't work.  Anyone know how to do
this correctly?

f[(x_Real | x_Integer) : 2.5] := x^2;
where f[3] = 9
and f[1.5] = 2.25
and f[] = 6.25

Follow-Ups:
- Re: Pattern Syntax for Alternate Heads with Default Value
  - From: Fred Simons <f.h.simons@tue.nl>
- Re: Pattern Syntax for Alternate Heads with Default Value
  - From: Christoph Lhotka <christoph.lhotka@fundp.ac.be>
- Re: Pattern Syntax for Alternate Heads with Default Value
  - From: Bob Hanlon <hanlonr357@gmail.com>
- Re: Pattern Syntax for Alternate Heads with Default Value
  - From: Adriano Pascoletti <adriano.pascoletti@uniud.it>

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