Re: Default argument and conditional pattern question
- To: mathgroup at smc.vnet.net
- Subject: [mg61812] Re: [mg61796] Default argument and conditional pattern question
- From: Bob Hanlon <hanlonr at cox.net>
- Date: Mon, 31 Oct 2005 01:17:06 -0500 (EST)
- Reply-to: hanlonr at cox.net
- Sender: owner-wri-mathgroup at wolfram.com
callLevelAndPrintResults[list_List, lev_List:{1}] :=
Module[{}, some stuff] /;
Length[lev] == 1 && Depth[lev] == 2;
Bob Hanlon
>
> From: "Matt" <anonmous69 at netscape.net>
To: mathgroup at smc.vnet.net
> Date: 2005/10/30 Sun AM 12:43:28 EDT
> Subject: [mg61812] [mg61796] Default argument and conditional pattern question
>
> Hello,
> This works (I want the second argument (if supplied) to be a list of
> length 1 and a depth of 2 (meaning no sublist), and if it is not
> supplied, I want the default value to be {1})
>
> callLevelAndPrintResults[list_List, lev : (_List?(Length[#] == 1 &&
> Depth[#] == 2 &)) : {1}] := Module[some stuff]
>
> Using the /; conditional construct, I could not get default values and
> a condition to work together. So, for example, this works:
>
> callLevelAndPrintResults[list_List, lev_List /; Length[lev] == 1] :=
> Module[some stuff]
>
> but I couldn't figure out the syntax to get something like this to
> work:
>
> callLevelAndPrintResults[list_List, lev:(_List /; Length[lev] ==
> 1):{1}] := Module[some stuff]
>
> I know it's mere semantics, but I'm trying to figure out what I can,
> and cannot do with these types of things.
>
> Thanks,
>
> Matt
>
>