Fastverse R

Expert guidance for the fastverse in R — the high-performance suite built on data.table, collapse, kit and magrittr, loaded with library(fastverse). Covers how the loader itself works (fastverse_extend/detach/reset/sitrep/ update/child, .fastverse project config files, options, OpenMP threading across the three multithreaded packages), the kit API (psum/pmean/pfirst/ plast/fpmin/fpmax/prange/pany/pall/pcount parallel statistical functions, vswitch/nswitch vectorized and nested switches, iif/nif, topn, charToFact, countOccur, uniqLen, setlevels, psort), the data.table API ([i, j, by], := and set() reference updates, .SD/.N/.I/.GRP/.BY, GForce, froll* rolling functions, keyed/rolling/non-equi joins and foverlaps, fread/fwrite, set* helpers, copy/rowid/rleid/setattr/transpose/nafill/shift), the magrittr operators (%>%, %<>%, %$%, %T>%, extract, set_names), and above all HOW THE FOUR PACKAGES DIVIDE THE WORK — when to reach for collapse versus data.table versus kit, with measured timings. Use this skill WHENEVER the user is writing or reviewing R code that loads the fastverse, data.table, collapse or kit; whenever they mention fastverse, data.table, kit, magrittr, .fastverse files, fastverse_extend, setDTthreads, kit.nThread, DT[i, j, by], :=, .SD, GForce, frollmean/frollapply, rolling or non-equi joins, fread/fwrite, psum/pmean/topn/vswitch/nswitch/iif/nif; and whenever they ask which of these packages to use for a task, how to combine them, or how to speed up an R data pipeline. Also use it when translating dplyr/base R/pandas code to a fast R stack, when a script mixes data.table and collapse, and when working with large data, panels, matrices, or spatial (sf) data frames in R. REQUIRES the companion skill collapse-r, which documents the collapse API itself. This skill deliberately does not duplicate it: it covers the other three packages, the loader, and the division of labour between all four. Load collapse-r alongside this one and delegate to it for anything that turns on how a collapse function behaves.

mkdir -p ~/.claude/skills/fastverse-r
curl -L https://claudskills.com/skills/fastverse-r/SKILL.md \
  -o ~/.claude/skills/fastverse-r/SKILL.md

@misc{fastverse-r-2026,
  author    = {fastverse},
  title     = {Fastverse R [Claude Code skill]},
  year      = {2026},
  publisher = {ClaudSkills},
  url       = {https://claudskills.com/skills/fastverse-r/}
}