# Package groovy.typecheckers

## Package groovy.typecheckers Description

Custom type checking extensions for compile-time validation.

FormatStringChecker, NullChecker, RegexChecker, PurityChecker extend type checking capabilities for DSLs and domain-specific validation.

- Class Summary
  Class | Description
  --- | ---
  FormatStringChecker | Checks at compile-time for incorrect format strings in format methods such as `printf` and `String.format`.
  ModifiesChecker | A compile-time checker that verifies method bodies comply with their `@Modifies` frame condition declarations.
  NullChecker | A compile-time type checker that detects potential null dereferences and null-safety violations in code annotated with `@Nullable`, `@NonNull`, and `@MonotonicNonNull` annotations.
  PurityChecker | A compile-time checker that verifies `@Pure` methods have no side effects.
  RegexChecker | Checks at compile-time for cases of invalid regex usage where the actual regex string can be identified (e.g. inline or defined by a local variable with an initial value or a field with an initial value).

- Annotation Type Summary
  Annotation Type | Description
  --- | ---
  FormatMethod | If this annotation is attached to a Formatter.format-like method, then when type-checking calls to the method, it will be a candidate method checked by FormatStringChecker.