derive is a toplevel attribute that asks Coalton to generate instances for a define-type or define-struct.

Syntax

(derive ⟨class⟩...)
(define-type ...)

Semantics

  • derive must appear immediately before a compatible define-type or define-struct.
  • It applies to the next definition, not to arbitrary expressions.
  • Coalton only derives supported classes, and the definition’s fields must supply the required instances.
  • Multiple classes can be derived in one attribute.
  • Supported classes: Eq, Hash, Default, Show

Example

(derive Eq Hash)
(define-struct Point
  (x UFix)
  (y UFix))