Re: Calc: `*' binds more strongly than `/'

[Christian Schlauer <cs-muelleimer-rubbish.bin@arcor.de>]

Jay Belanger <belanger@truman.edu> writes:

> Stefan Monnier <monnier@iro.umontreal.ca> writes:
> ...
>> If there are too many existing calc-scripts that would be
>> broken by such a change, fine, but if this only mostly affects interactive
>> use, then changing it would make a lot of sense.
>
> While several people have said the current behavior is convenient for
> interactive use, I would hope (and expect) that there aren't any
> calc-scripts depending on this behavior.  But it'd be nice to know for
> sure. 

You are the maintainer of Calc -- do you have any contact to package
authors or users of packages that make use of Calc? I only know about
Org-mode, see below. What about table.el?

The tables in Org-mode use Calc. That is a non-interactive use of
Calc, isn't it:

| Value | Percentage |
|-------+------------|
|    17 |            |
|    56 |            |
|    42 |            |
#+TBLFM: $2=$1/65*100

The `#+TBLFM:' line is a Calc-script, and some of them would break, if
they rely on the precedence of multiplication, like this example. But
nevertheless I think Calc's behaviour could (and should) be changed,
because:

- Existing tables aren't automatically recalculated when you open the
  file, you have to do `C-u C-c C-c' in the table. So there is no
  `immediate' damage. But even better:

- Org-mode could keep the existing Calc behaviour for existing tables
  but use the `new' more standards-conforming Calc behaviour when the
  script line `#+TBLFM:' starts with `#+TBLFMv2:' or something
  similar, which could be Org-mode's new default as soon as Calc has
  been modified.

So regarding Org-mode, nothing will break, I think.

> Perhaps after the release I could add a customizable variable,
> `calc-multiplication-has-precedence' (default t), and then anyone that
> wants to can set it to nil and try out the different behavior.

Rather make the default nil so that new users can use Calc and Org
like *any* pocket calculator or *any* spreadsheet...

WDYT?

Regards,

Christian