The base packages available at the assumed R version (all of them if omitted). A package counts as
available when that R release lies within the range it was part of core; e.g. parallel (added in R
2.14.0) is absent for an assumed R 2.10, and long-merged packages like ctest are absent for modern R.
The newest release is served from the precomputed RBasePackageStore.current array.
Every other version is computed once and memoized, so this never recomputes on repeated calls.
The base packages available at the assumed R version (all of them if omitted). A package counts as available when that R release lies within the range it was part of core; e.g.
parallel(added in R 2.14.0) is absent for an assumed R 2.10, and long-merged packages likectestare absent for modern R.The newest release is served from the precomputed RBasePackageStore.current array. Every other version is computed once and memoized, so this never recomputes on repeated calls.