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From: dh on 30 Mar 2010 06:02
Hi,
you nay find a listing of precedences in the Help under:
tutorial/OperatorInputForms
Daniel


On 29.03.2010 14:20, guerom00 wrote:
> Hello all,
>
> Just a quick question : what are the priority between all those
> operators ? I mean :
> - what is f@x//g ? Is it f[g[x]] or g[f[x]]
> - what is f@@{a,b}[[2]] ? Is it f[b] or (f[a,b])[[2]]
>
> You see what I mean... What are the rules for the priority of all
> those operators ?
>
> TIA :)
>


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Daniel Huber
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From: guerom00 on 30 Mar 2010 06:02
Thank you for all the responses :)

From: Norbert Marxer on 30 Mar 2010 06:03
On Mar 29, 2:20 pm, guerom00 <guero...(a)gmail.com> wrote:
> Hello all,
>
> Just a quick question : what are the priority between all those
> operators ? I mean :
> - what is f@x//g ? Is it f[g[x]] or g[f[x]]
> - what is f@@{a,b}[[2]] ? Is it f[b] or (f[a,b])[[2]]
>
> You see what I mean... What are the rules for the priority of all
> those operators ?
>
> TIA :)

Hello

Enter "tutorial/OperatorInputForms" in the text field in the Help
Documentation Center, hit return and scroll down to a long table which
gives you the precedence of all the operators.

A quick way to find out is also: select a symbol in the middle of your
expression, press "Ctrl ." and you will see whether Mathematica binds
to the left or right.

Best Regards
Norbert Marxer

From: Albert Retey on 30 Mar 2010 06:03
Am 29.03.2010 14:20, schrieb guerom00:
> Hello all,
>
> Just a quick question : what are the priority between all those
> operators ? I mean :
> - what is f@x//g ? Is it f[g[x]] or g[f[x]]
> - what is f@@{a,b}[[2]] ? Is it f[b] or (f[a,b])[[2]]
>
> You see what I mean... What are the rules for the priority of all
> those operators ?
>
> TIA :)
>
I think that this is all documented somewhere, unfortunately its not
that easy to find. On the other hand I hardly ever find it necessary to
look that stuff up, thanks to FullForm I will always get the actual
rules shown, including not only undocumented features but also potential
bugs :-)

FullForm[f@x//g]
FullForm[Hold[f@@{a,b}[[2]]]]

If in doubt, I usually use the explicit function names and not the
shortcuts, that is Apply instead of @@ and [] instead of @ or // and Map
instead of /@ . Using the longer FullForm-Syntax always makes the
priorities explicit, which I often like better than saving a few
letters/keystrokes...


hth,

albert


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