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The Piece Table - the Unsung Hero of Your Text Editor

Darren Burns on January 24, 2019

The piece table is the unsung hero data-structure that is responsible for much of the functionality and performance characteristics we’ve come to e...

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Isaac Lyman • Jan 24 '19

This is a great article. It reminds me a little of the "Delta" structure used by QuillJS. The document itself is represented as an array of objects, but updates are represented atomically as new objects of type retain, insert, or delete. I don't think it offers the same performance advantages as a true piece table, but it does provide some flexibility about how you build the document and respond to changes.

Darren Burns • Jan 24 '19

Thanks Isaac :)

dAVE Inden • Jan 24 '19

Great post. I had never heard of this data structure until now. It makes a lot of sense how it could be implemented to build a text editor and would be much more performant than storing things in an array. It is also great to see the kinds of things used to build the tools many use to build tools that many others will use. Thanks for writing this!

Darren Burns • Jan 24 '19

Thanks very much!

SriHarsha Sreenath • Jan 25 '19

Very well written article. Thanks for introducing us to a new data structure.

Darren Burns • Jan 25 '19

Thanks 🙂

aligear • Jan 24 '19

Thanks for the enlightenment! Great article which gives you where to start looking to understand how text editors works internally.

Darren Burns • Jan 24 '19

Thank you so much! Really appreciate your feedback 🙂

Mihail Malo • Jan 27 '19

Very accessible writeup, thank you, I was able to share this with many people.
Could you maybe make a follow up comparing and contrasting the Piece Table with the Rope data structure for text editing?

Darren Burns • Jan 27 '19

I'm really happy to hear you found it accessible, that was my main goal :)

Unfortunately, I've never studied or implemented a rope in the past so it would be difficult to give an informed view of how they compare. If I ever take the time to learn about ropes, I'll probably end up writing about them, though!

Thanks for sharing the post too.