Re: Infix doesn't worj with precedence and grouping
- To: mathgroup at smc.vnet.net
- Subject: [mg113722] Re: Infix doesn't worj with precedence and grouping
- From: Andrea <btlgs2000 at gmail.com>
- Date: Tue, 9 Nov 2010 03:52:33 -0500 (EST)
- References: <ib0l9q$gio$1@smc.vnet.net>
On Nov 5, 11:12 am, Dims <dim... at hotmail.com> wrote:
> It is told in help, that
>
> Infix[expr,h,precedence,grouping] can be used to specify how the
> output form should be parenthesized.
>
> but actually it doesn't work:
>
> Format[EClass[x___]] := Infix[{x}, "=", 290, None]
> In[40]:= EClass[a, b, c]
> Out[40]= Infix[{a, b, c}, "=", 290, None]
>
> while
>
> In[65]:= Format[EClass[x___]] := Infix[{x}, "="]
> In[66]:= EClass[a, b, c]
> Out[66]= Infix[{a, b, c}, "="]
>
> works.
>
> So how to specify precedence for infix format?
>
> Thanks.
It seems that the frontend only display the four argument form
correctly only in OutputForm.
Try
>Infix[{x,y,z}, "=", 290, None] // OutputForm
and you'll get
>x=y=z
I think you can solve this problem adding the following lines to your
init file
Unprotect[Infix];
Format[Infix[a_, b_, c_, d_], StandardForm] :=
Format[Infix[a, b, c, d], OutputForm];
Protect[Infix];