Data Frame Joins Leveraging 'data.table' // Extends 'data.table' join functionality, lets it work with any data frame class, and provides a familiar 'x'/'y'-style interface, enabling broad use across R. Offers NA-safe matching by default, on-the-fly column selection, multiple match-handling on both sides, 'x' or 'y' row order, and a row origin indicator. Performs inner, left, right, full, semi- and anti-joins with equality and inequality conditions, plus cross joins. Specific support for 'data.table', (grouped) tibble, and 'sf'/'sfc' objects and their attributes; returns a plain data frame otherwise. Avoids data-copying of inputs and outputs. Allows displaying the 'data.table' code instead of (or as well as) executing it.