collapse is a large C/C++-based infrastructure package facilitating complex statistical computing, data transformation, and exploration tasks in R - at outstanding levels of performance and memory efficiency. It also implements a class-agnostic approach to R programming, supporting vector, matrix and data frame-like objects and their popular extensions ('units', 'integer64', 'xts', 'tibble', 'data.table', 'sf', 'pdata.frame'), enabling its seamless integration with the bulk of the R ecosystem. This article introduces the package's key components and design principles in a structured way, supported by a rich set of examples. A small benchmark demonstrates its computational performance.
Sebastian Krantz (Thu,) studied this question.