Jadpo is experimental and not ready for production. These docs follow the compiler's main branch as of 5 Nov 2026. What's built · Install 0.3.0

ReferenceErrors

`type.rule_name_taken`

Rule is named like a field, another rule or invalid.

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

A rule's name is what an attempt's arm and a failure's report call it, so no field or other rule of the type shares it, and it is never invalid:

example

type Moment = Instant {}type Booking = Object {    starts: Moment    ends: Moment    rule ends: ends > starts}

jadpo checkcheck failed: 1 error, 1 file

error A rule can't be called ends here

--> main.jadpo:6:10

  |6 |     rule ends: ends > starts  |          ^^^^ name taken

reason: Booking has a field ends; a rule's name is its own, so ends: in an attempt or a report can only mean one thing.
next: Give the rule a name of its own that says what it checks (agent)
rule: type.rule_name_taken
help: https://jadpo.dev/docs/errors/type.rule_name_taken

Markdown for agents: /docs/errors/type.rule_name_taken.md.Built from Jadpo main at aee2e8f.