type.temporal_zone_required: Your code formats an Instant for people to read without saying which time zone to show it in

Your code formats an Instant for people to read without saying which time zone to show it in.

Area 10, Configuration; not declinable; the next step is usually the agent's.

Why Jadpo refuses it

An Instant is one moment for everyone. Its date and clock time depend on where it is read: late evening in London is already the next morning in Tokyo. The server's own zone is never used, because it says nothing about the reader, so zone: says which zone to show the moment in.

What it looks like

main.jadpo:

example

type OrderedAt = Instant {}function placed_label(ordered_at: OrderedAt, reader_locale: Locale) -> PresentationText {    return text.format(ordered_at, locale: reader_locale, format: TimeFormat.date_long)}

jadpo checkcheck failed: 1 error, 1 file

error text.format needs the zone to show OrderedAt in

--> main.jadpo:4:12

  |4 |     return text.format(ordered_at, locale: reader_locale, format: TimeFormat.date_long)  |            ^^^^^^^^^^^ no `zone:`

reason: An Instant is one moment for everyone, and its date and clock time depend on where it is read; the server never guesses a zone, so zone: says which.
next: Add zone: ... with the reader's zone, such as zone: Zone.europe_london (agent)
rule: type.temporal_zone_required
help: https://jadpo.dev/docs/errors/type.temporal_zone_required

(agent) at the end of the next: line means your coding agent can make the fix itself.

How to fix it

If readers are in different zones, take the reader's zone as a parameter and give it as zone:. main.jadpo becomes:

example

type OrderedAt = Instant {}function placed_label(    ordered_at: OrderedAt,    reader_zone: Zone,    reader_locale: Locale) -> PresentationText {    return text.format(        ordered_at,        zone: reader_zone,        locale: reader_locale,        format: TimeFormat.date_long    )}

Each reader sees the date as it was where they are.

If every reader is in one place, such as the customers of a shop in London, give that zone. main.jadpo becomes:

example

type OrderedAt = Instant {}function placed_label(ordered_at: OrderedAt, reader_locale: Locale) -> PresentationText {    return text.format(        ordered_at,        zone: Zone.europe_london,        locale: reader_locale,        format: TimeFormat.date_long    )}

Every reader sees the date as it was in London, wherever they are.

Why Jadpo refuses it

What it looks like

How to fix it

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