New metric prefixes

[0xflotus]

The Wikipedia site of the metric prefixes shows new unit prefixes:

Name	Symbol	Base 10
quetta	Q	1e30
ronna	R	1e27
ronto	r	1e-27
quecto	q	1e-30

It was adopted by BIPM in 2022

With insect I can add two datasizes like Petabyte and Terabyte.

2 PB + 1 TB
= 2.001 PB

But it is not possible to add a Quettabyte and an Exabyte.

Please implement the new metric prefixes to allow this.

[sharkdp]

Sounds good. Note that we have a slightly more complete set for binary prefixes, if you're mostly interested in data sizesa. They go up to up to yobi (YiB):

insect/src/Insect/Parser.purs

Lines 157 to 190 in 7544300

	prefixDict ∷ Dictionary (DerivedUnit → DerivedUnit)
	prefixDict = Dictionary
	[ Q.kibi ==> ["kibi", "Ki"]
	, Q.mebi ==> ["mebi", "Mi"]
	, Q.gibi ==> ["gibi", "Gi"]
	, Q.tebi ==> ["tebi", "Ti"]
	, Q.pebi ==> ["pebi", "Pi"]
	, Q.exbi ==> ["exbi", "Ei"]
	, Q.zebi ==> ["zebi", "Zi"]
	, Q.yobi ==> ["yobi", "Yi"]
	, Q.atto ==> ["atto", "a"]
	, Q.femto ==> ["femto", "f"]
	-- peta and mega have to be up here (before pico and milli) in order for the
	-- prefixes ('p' and 'm') not to be parsed as 'pico' or 'milli'.
	, Q.peta ==> ["peta"]
	, Q.mega ==> ["mega"]
	, Q.pico ==> ["pico", "p"]
	, Q.nano ==> ["nano", "n"]
	, Q.micro ==> [ "micro"
	, "u" -- u for micro
	, "µ" -- Micro sign U+00B5
	, "μ" -- Greek small letter mu U+039C
	]
	, Q.milli ==> ["milli", "m"]
	, Q.centi ==> ["centi", "c"]
	, Q.deci ==> ["deci", "d"]
	, Q.hecto ==> ["hecto", "h"]
	, Q.kilo ==> ["kilo", "k"]
	, Q.mega ==> ["M"]
	, Q.giga ==> ["giga", "G"]
	, Q.tera ==> ["tera", "T"]
	, Q.peta ==> ["P"]
	, Q.exa ==> ["exa", "E"]
	]

[0xflotus]

Sounds good. Note that we have a slightly more complete set for binary prefixes, if you're mostly interested in data sizesa. They go up to up to yobi (YiB):

insect/src/Insect/Parser.purs

Lines 157 to 190 in 7544300

	prefixDict ∷ Dictionary (DerivedUnit → DerivedUnit)
	prefixDict = Dictionary
	[ Q.kibi ==> ["kibi", "Ki"]
	, Q.mebi ==> ["mebi", "Mi"]
	, Q.gibi ==> ["gibi", "Gi"]
	, Q.tebi ==> ["tebi", "Ti"]
	, Q.pebi ==> ["pebi", "Pi"]
	, Q.exbi ==> ["exbi", "Ei"]
	, Q.zebi ==> ["zebi", "Zi"]
	, Q.yobi ==> ["yobi", "Yi"]
	, Q.atto ==> ["atto", "a"]
	, Q.femto ==> ["femto", "f"]
	-- peta and mega have to be up here (before pico and milli) in order for the
	-- prefixes ('p' and 'm') not to be parsed as 'pico' or 'milli'.
	, Q.peta ==> ["peta"]
	, Q.mega ==> ["mega"]
	, Q.pico ==> ["pico", "p"]
	, Q.nano ==> ["nano", "n"]
	, Q.micro ==> [ "micro"
	, "u" -- u for micro
	, "µ" -- Micro sign U+00B5
	, "μ" -- Greek small letter mu U+039C
	]
	, Q.milli ==> ["milli", "m"]
	, Q.centi ==> ["centi", "c"]
	, Q.deci ==> ["deci", "d"]
	, Q.hecto ==> ["hecto", "h"]
	, Q.kilo ==> ["kilo", "k"]
	, Q.mega ==> ["M"]
	, Q.giga ==> ["giga", "G"]
	, Q.tera ==> ["tera", "T"]
	, Q.peta ==> ["P"]
	, Q.exa ==> ["exa", "E"]
	]

Are zetta, yotta, yocto and zepto also missing?

It's not possible to convert 1e21 m to Zm.

1e21 m -> Zm
 1e+21 m ➞ Zm
 Unknown identifier: Zm

[triallax]

@sharkdp do we want to have this in our next release?

[sharkdp]

I would hope it could be an easy thing to add. Unless this creates new "conflicts". Like for example, if <new SI prefix>+<existing unit that takes an SI prefix>==<name of other existing unit>. We wouldn't expect any such conflicts within SI, of course. But maybe with one of the non-standard units that we also support. Examples for a clash from the past: f(femto)+t(ton)==ft(feet).

[triallax]

Hmm, I'm not motivated enough to check for conflicts at the moment, so I'm leaving it for later (or for somebody else :P), unless you want to work on it of course.

[sharkdp]

If course. I don't think we need to manually check for conflicts. I think we have parametrized tests in place that make sure that units with prefixes are properly parsed

[signalno11]

is there any reason P and M aren't defined for peta and mega? From what I can tell, the parser is in fact case sensitive.

Ignore me, I just saw that they are defined separately, probably for parsing reasons.