Maintaining state of document concurrently edited by two computing systems by determining locations of edits based on inverse transformations

A non-transitory computer-readable storage medium comprising instructions stored thereon for maintaining a current state of a document that is concurrently being edited by at least a first user associated with a first computing system and a second user associated with a second computing system, the instructions, when executed by at least one processor, being configured to cause the first computing system to at least:

• for each of multiple remote edits of the document received from the second computing system that have not already been applied to the document by the first computer:
• for each of multiple local edits to the document performed by the first computing system:
• determine whether the local edit to the document performed by the first computing system has been recognized by the second computing system;
• and
• if the local edit to the document performed by the first computing system has not been recognized by the second computing system, add an inverse transformation of the local edit to the document performed by the first computing system to a collection of unrecognized edits;
• and
• perform the inverse transformation(s) included in the collection of unrecognized edits on the document;
• apply the remote edit to the document at a location determined based on an original location of the remote edit and the inverse transformations performed based on the collection of unrecognized edits;
• and
• perform each of the multiple local edits to the document.

A method for maintaining a current state of a document that is concurrently being edited by at least a first user associated with a first computing system and a second user associated with a second computing system, the method comprising the first computing system performing at least:

• in response to receiving a remote edit from the second computing system that has not been performed by the first computing system, generating a collection of inverse transformations of an index of the document, the generating the collection of inverse transformations including:
• determining that at least one local edit remains to be added to a collection of local edits;
• determining that the at least one local edit is asymmetric;
• and
• adding an inverse transformation of the at least one asymmetric local edit to the collection of inverse transformations;
• determining a location within the document to perform a remote edit by the second computing system based on the collection of inverse transformations of the index of the document;
• performing the remote edit to the document at the determined location based on the remote edit by the second computing system;
• and
• performing at least one local edit to the document based on the collection of local edits.