Don't Move the Text: Ropes, Gap Buffers and Piece Tables

Deep End Era. Engineering with Sankalp · Oct 28, 2026 · 58m

In Montréal, a forty-megabyte lab log makes a text editor eat over a gigabyte of memory and crash. In the finale of The Deep End's Data Structures series, editor lead Yuki Tanaka and new engineer Diego Hernández work through how editors really store text: Emacs's gap buffer, the rope from Xerox PARC, the piece table that began in one of the first WYSIWYG editors, and the 2018 rewrite that let Visual Studio Code open files with millions of lines. Then a look back at all twenty-one parts and the one idea that ties them together. Yuki and Diego are fictional; the editors, papers and engineers…