The Internal Sub-Editor

There are many ways to decompose the implementation of a text editor into smaller pieces. This book analyzes one particular decomposition: that into a sub-editor to manage the test being edited, redisplay and the user-oriented commands. (There are no other pieces: when these have been assembled, the editor is complete.) This particular decomposition was chosen for two reasons. First, it is a natural one with one with relatively simple interfaces between the parts. Second, it has been chosen for any different implementations: it is thus known to be a decomposition that works well. This chapter covers the internal sub-editor. The following chapters describe the other parts.