Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2005
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2005

[Date Index] [Thread Index] [Author Index]

Search the Archive

named pattern variable scoped as global, should be local

  • To: mathgroup at smc.vnet.net
  • Subject: [mg56696] named pattern variable scoped as global, should be local
  • From: leenewman at gmail.com
  • Date: Wed, 4 May 2005 00:33:07 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

When using a named pattern variable within a module, it should be
scoped locally within the pattern.  However, this does not seem to work
as advertised.  For example, shouldn't the pattern variable x in the
statements below be local to the pattern?  Does anyone know whether
this is a bug, or whether I am just missing something about the usage
of variables in patterns/condition constructs?

(* this returns 14! *)
x = 7;
Module[{x},{1, 2, 3} /. x_ -> 2x];

(* this returns {2,4,6}, assuming q is not globally defined. *)
Remove[q];
Module[{q},{1, 2, 3} /. q_ -> 2q];


Lee


  • Prev by Date: Re: debugging
  • Next by Date: Variant of inner Product ...
  • Previous by thread: A bug in the documentation?
  • Next by thread: Re: named pattern variable scoped as global, should be local