groovy.contracts (Groovy 6.0.0-alpha-2)

Package groovy.contracts Description

Design-by-contract (DbC) support with compile-time assertion generation.

Stable annotations:

groovy.contracts.Requires – method precondition
@Ensures – method postcondition; closures may reference result and old
@Invariant – class invariant, also usable as a loop invariant on for / while / do-while loops
@Contracted – package- or class-level opt-in marker that enables contract processing

Incubating in 6.0.0 (semantics may evolve in a subsequent 6.x release):

@Modifies – frame condition declaring which fields and parameters a method may modify
@Decreases – a termination measure (a strictly-decreasing, well-founded variant) for a loop (per iteration) or a recursive method (per recursive re-entry)

Annotation Type Summary
Annotation Type	Description
Contracted
Decreases	Specifies a termination measure, either for a loop or for a (recursive) method.
Ensures
EnsuresConditions	Container annotation for multiple Ensures postconditions on the same target.
Invariant
Invariants	Container annotation for multiple Invariant declarations on the same type.
Modifies	Declares the frame condition for a method: the set of fields and parameters that the method is allowed to modify.
ModifiesConditions	Container for multiple Modifies annotations on the same method.
Requires
RequiresConditions	Container annotation for multiple Requires preconditions on the same target.

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