type.missing_field

An object value is built without one of the fields its type declares.

Area 2, Values and types; not declinable; the next step is usually the agent's.

Why Jadpo refuses it

An object value is written with its type name and every field, so a value always has what its type promises and nothing reads a field that was never set. A field that may hold nothing is declared T? and still given, as none, so leaving it empty is a choice you can see.

What it looks like

main.jadpo:

type Receipt = Output {    email: Email}function incomplete_receipt() -> Receipt {    return Receipt {}}

  |6 |     return Receipt {}  |            ^^^^^^^ fields missing

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

How to fix it

If the value has the field, give it in the block:

function incomplete_receipt(email: Email) -> Receipt {    return Receipt {        email: email    }}

Every Receipt now carries the email it is sent to.

If a receipt may have no email, declare the field Email? and give it as none:

type Receipt = Output {    email: Email?}function incomplete_receipt() -> Receipt {    return Receipt {        email: none    }}

Code that reads email now handles both cases, usually with match.

Related

• Objects
• Values that may be missing