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ReferencePhysical quantities

LanguageValues and typesStandard typesPhysical quantities

Volume

On this page

A volume: 500ml or 2litre.

Use it for liquids and capacity. An Area times a Length gives one.

Shape

One value, with no fields to fill in. As text it reads 2 cubic_metre.

Example

example
Volume(500ml)

text.parse(raw, as: Volume) reads one from text that comes from outside. Text that isn't one at all fails malformed, such as 5, 1.2.3 or five.

These operations give one: units.of and units.sum.

Good to know

  • It is held in cubic metres to 9 places.
  • == tells you whether two are the same, and < and list.sort_by compare and sort them.

In JSON

An object of its parts, in a request, a response or json.write:

json
{"value":"0.0005","unit":"cubic_metre"}{"value":"0.001","unit":"cubic_metre"}{"value":"2","unit":"cubic_metre"}

Details

Text form, storage, how it is shown, and operations

Volume is in the group Physical quantities, and has been in Jadpo since 0.1.0.

Text form

text.from writes one standard text form, the same form text.parse reads back: 0.0005 cubic_metre, 0.001 cubic_metre and 2 cubic_metre.

How it is stored

It is stored in one column named for the field, of type numeric(38, 9), holding the volume in cubic metres (m³). 0.001 cubic_metre is stored as 0.001.

How it is shown to people

text.format(value, locale:) shows it to people in their locale. A call may also give unit:.

With locale: Locale.en_gb:

Value Shown
0.0005 cubic_metre 0.0005 m³
0.001 cubic_metre 0.001 m³
2 cubic_metre 2 m³

Operations

  • units.in(value: Quantity, unit: QuantityUnit, scale: Int, rounding: Rounding) -> Decimal: value in unit, a unit of its kind, as a Decimal of scale places rounded by rounding: units.in(5km, LengthUnit.mile, scale: 2, rounding: Rounding.half_even) is 3.11.
  • units.of(value: Number, unit: QuantityUnit) -> Quantity: value of unit, an Int or a Decimal, as the quantity of unit's kind, converted exactly to the base unit and rounded half to even to the kind's scale: units.of(5, LengthUnit.mile).
  • units.sum(items: List<Quantity>) -> Quantity: The items added up, all of one kind; nothing for no items. A Temperature or a SoundLevel doesn't add to itself, so neither is summed.

It also takes text.parse, text.from, text.format, json.read, json.write and ==. How every standard type behaves says how they work.

Markdown for agents: /docs/types/type-volume.md.Built from Jadpo main at aee2e8f.