Re: Return in function
- To: mathgroup at smc.vnet.net
- Subject: [mg105710] Re: Return in function
- From: Raffy <raffy at mac.com>
- Date: Wed, 16 Dec 2009 06:18:37 -0500 (EST)
- References: <hftbe9$cjh$1@smc.vnet.net>
On Dec 11, 3:46 am, dh <d... at metrohm.com> wrote:
> Version 7.0.1
>
> Hello,
>
> I am not sure if this is a feature or a bug. If you use Return in an
>
> anonymous function, not only the return value is returned, but also
>
> "Return" itself. Consider:
>
> (If[# == 2, Return[a]; #, #]) & /@ {1, 2, 3}
>
> this gives:
>
> {1, Return[a], 3}
>
> The same thing happens with:
>
> Function[x, If[x == 2, Return[a]; x, x]] /@ {1, 2, 3}
>
> However, the following works as expected:
>
> f[x_] := (If[x == 2, Return[a]; x, x]);
>
> f /@ {1, 2, 3}
>
> Daniel
I completely agree with the Return[]-retardness. Proper Return[]-
behavior can be implemented using Catch/Throw, but the overhead is
atrocious.
To the naysayers: Mathematica is multi-paradigm; I see nothing wrong
with procedural code if it makes your code more readable and
maintainable.
I feel the most elegant improvement for future versions of Mathematica
would BlockReturn[], WithReturn[], and ModuleReturn[].
However, this would still leave naked Return[]'s in their current
state.