Re: Basic program structures in XSLT (was: Re: Data-d

On Fri, Dec 9, 2022 at 3:46 PM G. Ken Holman <gkholman@c...> wrote:

At 2022-12-08 10:52 -0700, C. M. Sperberg-McQueen wrote:
>are there analogous basic
>principles for program design which can be used to guide construction of
>a transformation in XSLT?

The focus/orientation of program design from the programmer's
perspective is the document order of the output, which is totally
independent of the document order of the input.

JLK: This is the most succinct description I've seen in this conversation, although others have mentioned it in addition to other concepts. XSLT enables rearranging content for context-specific purposes without rearranging the source.

(though being the same helps)

(many students would ask me about "going back" and "fixing" or
"adding to" content that already has been processed)

That and the already mentioned distinction of push and pull comprise
most of the introduction lecture in my XSLT class.

JLK - I've seen this described elsewhere as the difference between imperative and declarative. A long time ago, in an Arbortext far away, we talked about "Declarative vs. Procedural." Ian Williams boiled that down to a sentence: "an XSLT programmer does not define a sequence of actions, but specifies a number of rules that. the result should satisfy."

(I think a lot about this stuff these days. I have direct reports in India who are still learning. I need to find the easiest way to state stuff that often gets stated in any number of ways [see note about Arbortext above] over time.)