Energy

Energy, held in joules to 3 places, written 2kWh or 250kcal.

Physical quantities; ordered; since Jadpo 0.1.0.

Make one

text.parse(raw, as: Energy) reads one from its text; text that isn't one at all fails malformed, such as 5, "" or 1.2.3.

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

Text, JSON and storage

text.from writes its canonical text, the one form text.parse reads back. JSON sends an object of its parts.

It is stored in one column named for the field, of type numeric(38, 3), holding the energy in joules (J). 4184 J is stored as 4184.

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:

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.

Like every standard type, it also has the contract's own operations: text.parse, text.from, text.format, json.read, json.write and ==. It is ordered, so < and sorting take it. Every standard type meets one contract says how they work.