[xsl] Re: Pointers are weird

["Jacopille, David (he/him/his) (Boston) djacopille@xxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

Roger,

In HTML you can either reference a graphic with something like bimage.pngb
or you can literally paste the base64 encoded image directly into the HTML as
src=.  Both the ref and the image are data.  If you ask for the reference
value you will get the 9 character string bimage.pngb.  bimage.pngb is
the data of the reference, not the data of the image.

What a memory reference pointer like b0x00000000123ABCDEb, the characters
bimage.pngb, your finger (which doesnbt always point), and the string
bRogerb have in common are that they are abstractions that we interpret,
in some contexts, as referencing something else.  Which is the soul of a
pointer.

As in bRoger Roger?b  Only one word has the context of being a pointer
referring to you.

Dave





From: Roger L Costello costello@xxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>
Date: Friday, April 11, 2025 at 6:32b/AM
To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx <xsl-list@xxxxxxxxxxxxxxxxxxxxxx>
Subject: [xsl] Pointers are weird
Hi Folks, Occasionally friends come over to my home and I take them on a walk
around the neighborhood. When I see some thing interesting, I raise my hand
and position my index finger in the direction of the interesting thing. That
is, I point


Hi Folks,



Occasionally friends come over to my home and I take them on a walk around the
neighborhood. When I see some thing interesting, I raise my hand and position
my index finger in the direction of the interesting thing. That is, I point at
the interesting thing. It seems to me, that that is a real pointer--my index
finger pointing at some thing.



XML has pointers, e.g.,



<Book ref="SK">...</Book>



<Author id="SK">Stephen King</Author>



The value of the ref attribute, "SK", points to <Author id="SK">



"SK" doesn't look like a pointer to me. It looks like data. XML-aware tools,
however, treat it as a pointer to the <Author> element with a matching id
value.



HTML has pointers, e.g.,



<a href="#lesson1">...</a>



<p id="lesson1">...</p>



The value of the href attribute, "#lesson1", points to <p id="lesson1">



"#lesson1" doesn't look like a pointer to me. It looks like data. HTML-aware
tools, however, treat it as a pointer to the <p> element with a matching id
value.



I conclude that, in XML and HTML, a pointer is not a pointer at all. It's
data. It's data that is repeated elsewhere in the document: ("SK" ... "SK"),
("#lesson1" ... "lesson1"). For this "pointer fiction" to work, a tool that
processes the document must participate in the fiction and treat ref="SK" as
pointing to <Author id="SK"> and treat href="#lesson1" as pointing to <p
id="lesson1">.



Isn't that weird?



/Roger






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