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Re: Quit versus Clear["Global`*"]

  • To: mathgroup at smc.vnet.net
  • Subject: [mg121255] Re: Quit versus Clear["Global`*"]
  • From: DrMajorBob <btreat1 at austin.rr.com>
  • Date: Tue, 6 Sep 2011 03:57:45 -0400 (EDT)
  • Delivered-to: l-mathgroup@mail-archive0.wolfram.com
  • References: <201109042206.SAA21533@smc.vnet.net>
  • Reply-to: drmajorbob at yahoo.com

Quit appears to quit as soon as it is parsed, regardless of arguments...  
yet another poster found that, if it is the first line in a cell with  
other statements, Mathematica doesn't quit until those other statements  
are done, hence wiping out their effect.

Quit[e] the conundrum.

Bobby

On Mon, 05 Sep 2011 13:15:07 -0500, Andrzej Kozlowski <akoz at mimuw.edu.pl>  
wrote:

> Well, I see it differently. All Mathematica functions have the form  
> Head[arguments] where the number of arguments could be 0. Quit is  
> therefore a Mathematica function, like Print[], Return[]. In fact,  
> Quit[n] where n is an integer also works "passing the integer n as an  
> exit code to the operating system" whatever that means. On the other  
> hand, expressions of the form Abracadabra are normally just symbols and  
> normally they do not perform any actions. In fact, do you know of any  
> other example (except Quit) when when evaluating a symbols actually does  
> more than return a value (that usually happens in the case of global  
> constants, whose names begin with $,
>
> [1]:= $Version
>
> Out[1]= 8.0 for Mac OS X x86 (64-bit) (February 23, 2011)
>
> Note, by the way, that Abort[] works but Abort does not:
>
> In[3]:= Print[a];Abort[];Print[b]
> During evaluation of In[3]:= a
> Out[3]= $Aborted
>
> Print[a];Abort;Print[b]
> a
> b
>
> Andrzej Kozlowski
>
>
>
>
> On 5 Sep 2011, at 19:44, DrMajorBob wrote:
>
>> I, on the other hand, never saw Quit[] until this thread began.
>>
>> I suppose it figures that if Quit kills the kernel, then also Quit[any  
>> arguments or none] might also kill the kernel. (The other way 'round  
>> doesn't necessarily "figure", on the other hand.)
>>
>> Bobby
>>
>> On Mon, 05 Sep 2011 07:44:17 -0500, Andrzej Kozlowski  
>> <akoz at mimuw.edu.pl> wrote:
>>
>>> Actually (as far as I can tell) Quit is undocumented but Quit[] is:
>>>
>>> ?Quit
>>> Quit[] terminates a Mathematica kernel session.
>>>
>>> I thought you had made a mistake but I tired just Quit (without the  
>>> brackets) and was surprised (after all these years!) to see it work. I  
>>> am wondering if there are more cases like this?
>>>
>>> Andrzej Kozlowski
>>>
>>> On 5 Sep 2011, at 13:06, DrMajorBob wrote:
>>>
>>>> No. For that, you need:
>>>>
>>>> Quit
>>>>
>>>> Bobby
>>>>
>>>> On Sun, 04 Sep 2011 17:06:32 -0500, Themis Matsoukas  
>>>> <tmatsoukas at me.com>
>>>> wrote:
>>>>
>>>>> So, if I use ClearAll["Global`*"] at the beginning of a notebook and
>>>>> execute all the cells, is it the same as running on a fresh kernel?
>>>>>
>>>>> Themis
>>>>>
>>>>
>>>>
>>>> --
>>>> DrMajorBob at yahoo.com
>>>>
>>>
>>
>>
>> --
>> DrMajorBob at yahoo.com
>


-- 
DrMajorBob at yahoo.com




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