'Go'-Like Interfaces and 'Rust'-Like Traits with 'S7' R package s7contract version 0.1.0 Contract helpers built with 'S7' for expressing runtime protocols around ordinary 'S7' dispatch. Structural interfaces describe small sets of required 'S7' generics, while explicit traits record registered implementations with optional default methods and associated metadata. Optional runtime checks can validate argument and return specifications in contract-scoped evaluation. Software Depends: R (>= 4.3.0) Imports: S7 Suggests: knitr, rmarkdown, tinytest Sounkou Mahamane Toure <sounkoutoure@gmail.com> Comprehensive R Archive Network (CRAN) Sounkou Mahamane Toure [aut, cre] GPL (>= 3) 2026-05-07 application/tgz https://CRAN.R-project.org/package=s7contract doi:10.32614/CRAN.package.s7contract