Re: remove-elements-not-satisfying-the-predicate

On 2024-07-03, Paul Rubin <no.email@nospam.invalid> wrote:

Kaz Kylheku <643-408-1753@kylheku.com> writes:

The name filter doesn't tell me what is returned: the wanted
material or the unwanted material?

>
The term has been around forever, like in electronics: high pass
filters, low pass filters, etc.  It's almost always the wanted material
that comes out of the filter. 

Electronics filters (at least simple, passive ones like one-pole RC)
have only one output. There is no tap for the "filtered out" signal.

The "high pass" term alone tells you what passes onto that one and only
output.

"pass" would be an okay name for the function:

  (pass (lambda (x) (> x 3)) list)

  (reject (lambda (x) (> x 3)) list)

It's a "high pass filter" and not just a "high filter" because
the latter makes it unclear whether highs are rejected or passed!

It could be interpreted similarly to "UV filter" or "dust filter".


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