System and method for combining text editing and tree encoding for computer programs

A system and method for combining text editing and tree encoding for computer programs and related software. Source code for programs and the like are stored using a maintaining a structured tree representation comprising a plurality of nodes, including nodes associated with respective identifiers, operands, operators, variables, and flow control elements in the source code, and nodes associated with formatting aspects of a text-based representation of the source code. During program editing, a continuous loop of operations is performed to support interactive editing of the source code, including unparsing the structured tree representation to derive tokens, processing the tokens to generate an editable text-based representation of the source code, detecting edits to the source code via the text-based representation, and in response thereto generating one or more new tokens and/or deleting one or more existing tokens, parsing the tokens, and processing the parsed tokens to update the structure tree representation of the source code to reflect the edited source code.