Fast and Functional Data Structures R package Immutables version 1.0.1 Provides fast, side-effect free data structures, including catenable named lists, priority queues, double-ended queues, ordered sequences, and interval indices. Implementation is based on the finger-tree data structure of Hinze and Paterson (2006) <doi:10.1017/S0956796805005769>. Software Depends: R (>= 4.1.0) Imports: coro, Rcpp, lambda.r LinkingTo: Rcpp Suggests: covr, ggplot2, ggtext, igraph, IRanges, knitr, microbenchmark, pkgdown, pkgload, rmarkdown, rprojroot, rstackdeque, rticles, S4Vectors, scales, testthat (>= 3.0.0) Shawn T. O'Neil <shawn@tislab.org> Comprehensive R Archive Network (CRAN) Shawn T. O'Neil [aut, cre] MIT + file LICENSE (https://CRAN.R-project.org/package=Immutables/LICENSE) 2026-04-28 application/tgz https://CRAN.R-project.org/package=Immutables doi:10.32614/CRAN.package.Immutables