TrendLSW vs valr

valr reimplements bedtools-style genome interval arithmetic as tidyverse verbs backed by C++. Its long project has been closing the behavioural gap with bedtools — the book-ended interval semantics finally match in 0.10.0, three releases after the deprecation began. The July release also ends the assumption that intervals must be in memory: bed_map(), bed_intersect(), bed_subtract(), bed_coverage() and bed_window() accept a bigWig or bigBed path or URL where an interval table used to go.

Two arcs converge here. One is compatibility: min_overlap arrived with a deprecation warning in 0.9.0 and its default flipped from 0 to 1 in 0.10.0, so book-ended intervals are excluded by default as bedtools does, with the internal calculations in bed_closest() and friends deliberately left counting them. The other is the file-backed path, which grew out of the cpp11bigwig dependency adopted in 0.8.3 for read_bigwig() and re-exported in 0.9.0 — reading a file became querying one. Underneath, the C++ base keeps getting lighter: Rcpp swapped for cpp11, rlang cut to a single function, per-group memory copies removed from three verbs.

Only five verbs take a file argument today and bed_closest(), bed_glyph() and the statistical verbs do not, so extending the file-backed path across the rest of the API is the obvious follow-up. The deprecated tibble re-exports and the now-defunct n_fields argument suggest continued removal of the compatibility layer in the next minor release.