Energy

On this page

Shape
Example
Good to know
In JSON
Details

An amount of energy: 2kWh or 250kcal.

Use it for electricity used or food labels. For the rate at which energy is used, use Power.

Shape

One value, with no fields to fill in. As text it reads 3600000 J.

Example

example

Energy(2kWh)

text.parse(raw, as: Energy) 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 joules to 3 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":"0.5","unit":"J"}{"value":"4184","unit":"J"}{"value":"3600000","unit":"J"}

Details

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

Energy 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: 0.5 J, 4184 J and 3600000 J.

How it is stored

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.

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
`0.5 J`	`0.5 J`
`4184 J`	`4,184 J`
`3600000 J`	`3,600,000 J`

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-energy.md.Built from Jadpo main at aee2e8f.