Sanctuary

Every function is defined for all inputs, eliminating partial functions and reducing runtime errors like null pointer exceptions, as shown in comparisons with Ramda's partial functions.

Enforces type invariants with descriptive error messages during development, catching bugs early without silent failures, unlike Ramda's garbage-in-garbage-out approach.

Provides Maybe and Either types for composable error and optional value handling, fully compatible with the Fantasy Land specification for interoperability.

Built from smaller libraries like sanctuary-def and sanctuary-type-classes, allowing reuse in other contexts and reducing complexity compared to monolithic designs.