[OS X TeX] Problems customizing report.cls

[Herb Schulz]

On 4/15/05 7:55 PM, "Ross Moore" <ross at ics.mq.edu.au> wrote:

> Hi Herb,
> 
> On 16/04/2005, at 2:44 AM, Herb Schulz wrote:
> 
>> Howdy,
>> 
>> \p@ is a shorthand for a length of 1pt (i.e., it is a single token
>> rather
>> than 3 tokens).
> 
> Yes; the number of tokens to be handled is one aspect of the
> increased efficiency.
> 
> Another is that \p@ (or any control-sequence, for that matter)
> is a token for what is known as a 'pointer' in other computing
> paradigms. Thus processing the \p@ is just a matter of looking
> up its value in some internal table. This will get you quickly
> to the appropriate bit of memory where the value was pre-stored.
> 
> With  '1pt'  it's necessary to do more work, first parsing the
> tokens to check that they match the specifications for a <dimen>,
> and then allocating some memory to hold this newly-declared length.
> 
> Thus it's clearly better to use an existing pointer (such as \p@ )
> to refer to a constant quantity, when one already exists globally.
> 
> 
> 
>> Similarly, \z@ is shorthand for 0pt.
> 
> Also, \@ne , \tw@  etc, for numbers 1, 2, ...
> 
> Here there's just one token, but the memory-management
> aspects still could lead to a small increase in performance,
> if used repeatedly, say within looping constructions.
> 
> 
> Hope this helps,
> 
> Ross
> 

Howdy,

Thanks for the information. I'm used to thinking in terms of pointers and
pointers to pointers, etc., from my old days doing C at a Telecommunications
Firm.

Good Luck,

Herb Schulz
(herbs at wideopenwest.com)

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