Jadpo is experimental and not ready for production. These docs follow the compiler's main branch as of 30 Oct 2026. What's built · Install 0.1.0
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Reference: Values and types

Values and types · rule

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}
text
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_typecheck failed: 1 error, 1 file

Markdown for agents: /docs/errors/syntax.nullable_type.md.Built from Jadpo main at a707efb.