xled is sed and awk for tabular data: the field model of awk, the s///
substitution of sed, and the live in-memory buffer of ed, applied to
Excel-style ranges over CSV and DSV files.

Cells are addressed by column letter, by bracketed name, or by range, and
values stay stringly-typed with explicit casts, so leading zeros and long
identifiers survive intact.  It never reshapes the table, and every edit can
be previewed before it is committed.