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.invalid_pattern`

Pattern is not a supported regular expression.

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

A pattern must match the whole text and uses a subset of regular expressions without backreferences or lookaround (question 9):

example

type Doubled = Text {    pattern: "(a+)+\\1"}

jadpo checkcheck failed: 1 error, 1 file

error This pattern can't be used

--> main.jadpo:2:14

  |2 |     pattern: "(a+)+\\1"  |              ^^^^^^^^^^ backreferences are not allowed

reason: A pattern is a regular expression that must match the whole text, without backreferences or lookaround, so it runs in linear time and the same way on every target.
next: Rewrite the pattern without the unsupported part (agent)
rule: type.invalid_pattern
help: https://jadpo.dev/docs/errors/type.invalid_pattern

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