[src/trunk]: src/usr.bin/units units.lib: fix "surveyfoot" and kill off "brit...

[dholland <dholland%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/8ac08a675d9a
branches:  trunk
changeset: 371988:8ac08a675d9a
user:      dholland <dholland%NetBSD.org@localhost>
date:      Mon Oct 24 05:04:50 2022 +0000

description:
units.lib: fix "surveyfoot" and kill off "british".

The US survey foot is defined as 1200/3937 of a meter, whereas the
ordinary international foot is 0.3048 meter. These are almost, but
not quite the same.

Define the survey foot this way instead of defining an adjective unit
for the conversion, which is much less confusing even if the adjective
unit had a reasonable name. For the time being the fact that it was
called "british" remains thoroughly obscure.

diffstat:

 usr.bin/units/units.lib |  13 ++++++++-----
 1 files changed, 8 insertions(+), 5 deletions(-)

diffs (48 lines):

diff -r 0595d4c99296 -r 8ac08a675d9a usr.bin/units/units.lib
--- a/usr.bin/units/units.lib   Mon Oct 24 04:55:19 2022 +0000
+++ b/usr.bin/units/units.lib   Mon Oct 24 05:04:50 2022 +0000
@@ -1,4 +1,4 @@
-/      $NetBSD: units.lib,v 1.27 2022/10/24 04:55:19 dholland Exp $
+/      $NetBSD: units.lib,v 1.28 2022/10/24 05:04:50 dholland Exp $
 
 / primitive units
 
@@ -290,8 +290,6 @@
 league                 3 mi
 mil                    1e-3 in
 
-british                        1200|3937 m/ft
-
 / nautical
 / Historically, the nautical mile was 6080 feet (6080.2 in England)
 / but was changed to 1852 meters (6076 feet and change) in the 20th
@@ -304,6 +302,11 @@
 cable                  720 ft
 
 / surveying
+/
+/ The US survey foot is defined as 1200/3937 meters, as opposed to the
+/ ordinary international foot, which is 0.3048 meter (that's exactly
+/ 2.54 cm to the inch as defined above.)
+/ https://en.wikipedia.org/wiki/Foot_(unit)
 rod                    5.5 yd
 rd                     rod
 perch                  rd
@@ -311,7 +314,7 @@
 chain                  66 ft
 link                   66|100 ft
 furlong                        220 yd
-surveyfoot             british-ft
+surveyfoot             1200|3937 meter
 surveyyard             3 surveyfoot
 surveyorschain         66 ft
 surveyorslink          66|100 ft
@@ -356,7 +359,7 @@
 rood                   1.21e+3 yd
 
 / other
-geodeticfoot           british-ft
+geodeticfoot           surveyfoot
 geographicalmile       1852 m
 engineerschain         100 ft
 engineerslink          100|100 ft