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

Errors Values and types · rule

`type.redundant_nullability`

Type is already nullable.

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

example

type ProductName = Text {    max_length: 120}type Listing = Object {    subtitle: ProductName?}type ListingPreview = Object {    subtitle: Listing.subtitle?}

jadpo checkcheck failed: 1 error, 1 file

error Listing.subtitle already permits none

--> main.jadpo:10:15

   |10 |     subtitle: Listing.subtitle?   |               ^^^^^^^^^^^^^^^^^ nullable twice

reason: Listing.subtitle takes none from its declared type; a second ? adds nothing.
next: Remove the extra ? (agent)
rule: type.redundant_nullability
help: https://jadpo.dev/docs/errors/type.redundant_nullability

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