Re: Returnin pure function
- To: mathgroup at smc.vnet.net
- Subject: [mg58896] Re: Returnin pure function
- From: dh <dh at metrohm.ch>
- Date: Sat, 23 Jul 2005 05:32:03 -0400 (EDT)
- References: <dbq2gu$6vb$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi Bill,
the idea behind my question is a simple way to prematurely leave a function.
sincerely, Daniel
Bill Rowe wrote:
> On 7/21/05 at 3:46 PM, dh at metrohm.ch (dh) wrote:
>
>
>>Hi, I seems to me that there is a bug in the implementation of pure
>>functions. If somebody can explain the following behaviour it would
>>be interessting. If not, maybe Wolfram can contribute something.
>>Consider f[x_]:= If[x==0,Return[Error],x]; f /@ {1,0} gives
>>{1,Error} what is fine. Now replace the function by a pure
>>function: If[#==0,Return[Error],#]& /@ {1,0} this gives
>>{1,Return["Error"]}. The Return statement has not been evaluated.
>
>
> Why do you want to use Return in this manner?
>
> Either
>
> f[x_]:=If[x==0, Error, x]
>
> or
>
> f=If[#==0, Error, #]&
>
> will do what you want. That is,
>
> In[6]:=
> f[x_] := If[x == 0, Error, x];
> g = If[#1 == 0, Error, #1] & ;
> f /@ {0, 1} == g /@ {0, 1}
>
> Out[8]=
> True
> --
> To reply via email subtract one hundred and four
>