Re: [xsl] What is the relationship between transforming, mapping, and filtering?

Subject: Re: [xsl] What is the relationship between transforming, mapping, and filtering?
From: "Kurt Cagle kurt.cagle@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>
Date: Tue, 31 Aug 2021 22:13:34 -0000
*mapping*: the process of iterating through a list of items and
transforming each item in turn into a (potentially different) item.
Technically, the iteration and the map are different things, but almost all
map operations are usually done upon a sequence of some sort.
*filtering:* A filter is a mapping function on a list that returns either
that item if the function is true or a null value if the function for that
item returns false. The result of a filtering operation is a sequence that
is a subset of the original sequence.
*reducing:* A reduction is an operation on a sequence that creates an
aggregate structure from that sequence.
*wrapping:* A wrap encloses the results of a sequence within another
structure.
*transforming*: A transforming operation is one in which mapping,
filtering, wrapping, and reducing are applied via a pipeline to a given set
of input sequences to generate a new composite structure.

*Kurt Cagle*
Community/Managing Editor
Data Science Central, A TechTarget Property
kcagle@xxxxxxxxxxxxxx or kurt.cagle@xxxxxxxxx
443-837-8725


On Tue, Aug 31, 2021 at 10:58 AM Roger L Costello costello@xxxxxxxxx <
xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:

> Hi Folks,
>
> How do you define those terms? Are they synonymous? Is one a subset of
> another?
>
> By "mapping" I mean populating XML instances of one data standard with
> data from another data standard. For example, I am currently mapping a
> military air navigation data standard to a civilian air navigation data
> standard.
>
> By "filtering" I mean performing actions on data such as redacting,
> fuzzing, and zeroing. One could think of these actions as mapping: if I
> fuzz a lat/long location, I am essentially mapping the location to another
> location.
>
> By "transforming" I mean all the kinds of things you can do with XSLT.
>
> Is filtering a subset of mapping? Is mapping a subset of transforming?
>
> /Roger

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