47 Extents

An extent is somewhat the generalisation of a marker object within the text.

To be precise, An extent is a region of text (a start position and an end position) that is displayed in a particular face and can have certain other properties such as being read-only. Extents can overlap each other. SXEmacs efficiently handles buffers with large numbers of extents in them.

• Intro to Extents: Extents are regions over a buffer or string.
• Creating and Modifying Extents Basic extent functions.
• Extent Endpoints: Accessing and setting the bounds of an extent.
• Finding Extents: Determining which extents are in an object.
• Mapping Over Extents: More sophisticated functions for extent scanning.
• Extent Properties: Extents have built-in and user-definable properties.
• Detached Extents: Extents that are not in a buffer.
• Extent Parents: Inheriting properties from another extent.
• Duplicable Extents: Extents can be marked to be copied into strings.
• Extents and Events: Extents can interact with the keyboard and mouse.
• Atomic Extents: Treating a block of text as a single entity.