Insertoverwrite

Insertoverwrite is a term used in discussions of data editing and patching to describe a mode that blends insert and overwrite semantics at a specific position in a text or binary buffer. The term is not standardized and appears mainly in theoretical discussions, plugin documentation, and descriptions of editor features that mix insert and overwrite behaviors.

Semantics of insertoverwrite vary by implementation, but a common model describes an input payload of length L and an overlap width W, where 0 <= W <= min(L, remaining data). The operation first overwrites the next W existing units starting at the cursor with the first W units of the payload. The remaining L-W units are then inserted at the position immediately after the overwritten region, pushing the rest of the content to the right. If W = 0, the action is a pure insert; if W = L, it is a pure overwrite. If the available existing data after the cursor is shorter than W, the operation overwrites only what exists.

Contexts and usage: In practice, insertoverwrite is implemented as a configurable mode in some text editors, integrated development environments, or patching tools, particularly when a single operation must replace some material while adding new material in the same pass. It can be useful for inline expansions, applying mixed edits, or merging patches to fixed-length records.

Considerations: Because it modifies data in place and can change length, insertoverwrite affects indices, cursors, and undo histories. Tools implementing this mode typically expose the overlap width W as a user option or via scripting.

See also: insert, overwrite, overtype, patch, hybrid editing mode.