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

`syntax.nullable_type`

Nullable type written in another language's form.

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

A type that may hold none is written with ?.

example

type ProductName = Text {    min_length: 1}type Listing = Object {    name: ProductName    subtitle: ProductName | null}

jadpo checkcheck failed: 1 error, 1 file

error Jadpo writes ProductName?, not ProductName | null

--> main.jadpo:7:27

  |7 |     subtitle: ProductName | null  |                           ^^^^^^ write `ProductName?`

reason: T | null and T | undefined are types that may be missing in TypeScript, and T | None and Optional[T] in Python; Jadpo writes T?, which holds a T or none.
next: Write ProductName? (agent)
rule: syntax.nullable_type
help: https://jadpo.dev/docs/errors/syntax.nullable_type

Markdown for agents: /docs/errors/syntax.nullable_type.md.Built from Jadpo main at aee2e8f.