Changes in version 0.1.1                        

  - Adding the Literal type check
  - Adding the extend method to extend a preexisting list schema.
  - Adding NonNA() modifier — rejects any value that contains at least
    one NA.
  - Adding Between(min, max) — closed-interval numeric range constraint.
  - Adding Matches(pattern) — PCRE regex-constrained string type.
  - Adding NonEmpty() modifier — rejects zero-length vectors, lists, and
    zero-row data frames.

                 Changes in version 0.1.0 (2026-03-31)                  

  - Initial CRAN submission.